Audio magazine September 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
Even 18-year-old Bogen systems
A DAPT EASILY WITH NEW
SINGLE-KNOB VOLUME CONTROL
YOU CAN
CONVERT
TO STEREO
THE RIGHT WAY
.. . RIGHT NOW!
There's stereo in your future if you own a Bogen
system (or plan to buy one) . In fact, stereo conversion can be made right now on any Bogen
high-fidelity system made since 1940! Not just
an added second channel, but completely integrated, balanced-sound stereo. You pre-set tone
and volume controls only once, from then on
regulate volume of both channels simultaneously
from a single volume controI. That's the right
way to convert to stereo. Here's how :
r -------~
r- - -1)
~::~~,!~_-::~J
~J-=-r~J
STEREO TAPE'
I AND / OR DISC
~
r-----..,.
,
I
NEW
TUNER
,1
lt
I
STA I
II
r - - --,...
on
NEW
I
-' : :
AMPLIFIER IT--<, II
i
L..L..-l
I,....------J
'
L ______ ~I
~- ---- -~
'.l.j
,------, _J '"
I STEREO TAPE
I
OR DISC
P.-.-f
tt--<,/'''-II'I
,.,
~ 5TIO·A
\.--------l
\:.----~
~ ________ :J
----
SPEAKER
~-------:.ISPEAKER
A
You can convert to single volume control and easily balance your
• system with th e Bogen STAI Ste reo Adapter if you own any of
these Bogen or Chall enger high-fidelity amplifiers: AClO', DBlO.
DB114, DB125, DB130, PRlOO, PRlOOA, PXlO, PX15. Simply add the
STAl, your choice of speaker and a DB130, DB125 , DB1l4 or AClO· .
B
If you own either the Bogen RB115' or the Bogen RB140, you
• can convert with the Bogen STAI Stereo Adapter and the necessary second-ch annel components , including a DB1 30, DB125, DB114.
or AClO' amp li fier.
C
If you own any Bogen or Challenger high-fidelity amplifier manu• factured s ince 1940 or a Bogen high-fidelity receiver, you can
convert with the Bogen STlO-A Stereo Adapter-Amplifier and a
seco nd speak er system.
EASY AM-FM STEREO CO,NVERSION: To receive stereo broadcasts from si multaneous AM-FM transmission with your present
tuner, add the fo llowing Bogen tuners: with any AM tuner, the new
Bogen FM5l; with a ny FM tuner, the n ew Bogen AM91. With any
Bogen AM-FM tuner or receiver, add eith er the AM 9l or FM51.
·Series B or late r
··Sli ghtly hi gher tn th e \Vc st
YOU?' Bogen deale?' is ?'eady now
with complete information on how
to conve?'t YOU?' system to
ste?·eo . See him today!
, .. because it sounds bette?'
David Bogen Co .. P .O. Box 500 . Paloamus . New J e rsey · A Di v ision of The Siegle r Corporation
ManUfacturers of High-Fidelity Compon en t s, Public Address Equipment and Int e1'communication Systems.
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SEPTEMBER, 1958
VOL. 42, No.9
fo r Ultimate Fidelity
Successor to RADIO, Est. 1917.
*
I!!NCINI!!ERINC
MUSIC
SOU ND REPRODUCTION
C. G. McP roud, EdilOi' and Publishel'
Henry A. Schober, Business Manager
Harri e K. Richardson, Associate Editor
Linda Sueskind, Assistant Ed itor
J anet M. Dur gin, Production Manager
*outs tandln g hon ..
ors bestowed. un ..
solicited. by most
recogni zed testi ng
organizati on s.
Edgar E. Newman, Circulation Director
Sanfo rd L. Cahn, Advel'lising Dir'ector
Special R epresentativeW. A . Cook and Associates
161 East Grand Ave., Chicago II, Ill.
Mid West RepresentativeSanford R. Cowan, 300 W. 43rd St.,
New York 36, N . Y.
West Coast RepresentativeJames C. Galloway
6535 Wilshire Boulevard, Los Angeles 48, Calif.
-"(MU I'
""lfln.
Of
CONTENTS
Audioclinic-J oseph Giovanell-i .... ... .. .... ... .................. .... ... ....
Letters
........................................................ .
Audio ETC-Edward Tatnall Canby
Editor's Review
A Simplified Control Unit- Rob e1·t G. Chaplicle
Measurement of Amplifier Internal Impedance- W . H. Ande1'son
Stereophonic Recording and P layback Amplifier-Wayn e B. Denny
Sound Reproducing Systems- Monaural, Binaural, Monophonic, and Stereophonic- Ha1'ry F . Olson ....................................................................................................... .
Hybrid Feedbacks for Power Amplifiers- He1·bM·t I . K e1'oes
............. .
Hearing, the Determining Factor for High Fidelity Transmission-Part IIIHarvey Fletcher . .. ............................................................................................... .
The Stereo Phasing Problem- C. G. McProttd ......................... ..
A E S Convention
.................................................... ..
Equipment Review- Madison-Pielding Se1'ies 330 StM'eotttme1' and SM'ies 320
Ste1'eo Amplifie1'-Ha1'man-Ka1'don F-l0 PM Tun e1'
Chicago H igh Fidelity Show
. .. ...... . .......... .
New Literature
........................ ..
Record Revue- Edwa1'd Tatnall Canby
About Music-Ha1'0Id Lawrence
Coming H i-Fi Shows
Jazz and All T hat- Charles A. Rob M· tson
................... ..
New Products
Stereo Records Released Since August
Industry Notes & P eople
Advertising I ndex
2
6
12
14
17
22
24
28
30
34
38
40
42
46
52
60
66
67
68
72
78
87
88
COVER PHO TO- Stereo in the studio. Conductor Leonard Bernstein and violinist Isaac Stern confer during Columbia Masterworks recording session of the
Bartok Concerto for Violin. Musicians are member s of the New York Philharmonic orchestra.
AUDIO (title reglstered U. S. Pat. 011.) Is pubUshed monthly by RadIo MagazInes, Inc., Henry A. Schober, Pr ..ldeDt;
C. O. McProud, Secretary. Executive and Editorial Omces, 20 4 Front St., MIneola, N. Y. SubscrlptlOD rates-V. S.
PossessIons, Canada and MexIco, $4 .00 lor one year, $7. 00 tor two years, an otber couDtrles, $5. 00 per year. SIngle
toples 50¢. PrInted ID U.S.A. at Lancaster, Pa. All rlghla reserved. Entire contents copyrlgbted 1958 by RadIo Magazines.
IDC. Entered as Second Class Matter February 9, 1950 at tbe Post Omce. La ncaster. Pa. under t be Act 01 Marcb 3, 1 879.
RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y.
Postmaster : Send Fonn 3579 to AUDIO, P. O . Box 629, Mineola, N.Y.
AUDIO
•
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
No matter what your source of music
-FM , your own discs, or tape-you
will enjoy it at its best coming from
Sherwood 'scomplete home music center
. .. most honored of them all! Sherwood
tuners for example . . .
First to achieve under one microvolt
sensitivity for 20 db FM quieting increases station range to over 100 miles.
Other important features include the
new "Feather-Ray" tuning eye, auto·
matic frequency control , flywheel tun·
ing output level control and cathodefollower output.
Model S-2000 FM·AM Tuner S139.50 nel
Model S·3000 FM (onl y) Tuner S99.50 nel.
For co mDl ete s peci fi cation s. writ e D ept . A-9
ELECTRON IC LABORATORIES. INC.
4300 North Ca lifornia Avenu e. Chicago. IIl1nol.
Th e " c ompl ete high fi delity hom e mu si c c ente r."
AUDIOCLINIC??
JOSEPH GIOVAN ELLI :;,
AM receiver alignment
Q. What is t he correct proced11?"e to be fol·
lowed when aligning an .AM superhete1'0,
dyne 1'ece'iver? William Clifford, Chicago,
Ill.
A. No single proced ure will satisfy t he
alignment reqnirements of all receivers.
Therefore, the following information
should be used only in an emergency. Wh en
possible, consult t he se rvi ce notes for the
receiver to be aligned .
Figure 1 shows a top vi ew of a typiCll l
superheterodyne r eceive r, including the
lo cation s of some of th e trimmers and
slugs needed for per forming the alignm ent.
You will need an r.f. signal geneJ'a tol'
whose minimum coverage should be 4551400 kc. It will be com'eni ent if the gen ·
erator can be tone modulated. If it cannot.,
yo u will need a VTVM, which should be
connected across the a.v.c. line. Some reo
ceivers have a built-in v.t.v.m.-a tuning
eye. If, however, you can use tone modulation, you may connect an output metur
acro ss the speaker terminals or you may
use yom ear to determine sound output. I
have found that the ear gives as good r e·
sults as the meter.
.A l'i gnment Procedu1'e : 1. Connect t he
grouncl side of the generator to the r eceiver chassis. 2. Conn ect the hot side of
the generator to the grid of the mixer
through a low-value capacitor. 3. Ground
t he :ecei~er to a r adiator or waterpipc.
(OmIt thIS step if t he circuit is one of th e
AC-DC types. Failure to observe t his cau·
tion can result in a blown line fuse and / or
*3420 N ew7cirk .Ave., B1'00klyn 3, N . Y.
damage to the receiver. ) 4. Allow the generator to warm up for 15 minutes. 5.
Short th e oscilla tO t' stator to ground with
a heavy wire. Thi s will cause oscillations
to cease, preventing bea ts which co uld result in aligning t he i.f. stage at an incorrect freq uency. 6. Set the generator to
the con-ect Lf., which is probably 455 or
465 kc. If you g uess wrong, th e error will
probably not show up at all. Advance th e
volume control of t he r eceiver to its maximum clockwise positiou . 8. Set t he r.f. attenuator on the gener ator to a point where
defl ection of t he mete r pointer or th e t un ing eye just begins or t he ton e becomes
just audible. 9. Startin g from t he detector
adjust all i.f. trimme rs or slugs for maxi~
mum reading on yo ur measuring instrument. If the i.f. stage or stages are
severely out of alignm ent, it may be necessary to reduce the gain on the r.f. attenuator . in order to prevent overloadin g
the r eceIver and the measuring instru ment. This completes the alignment of t he
i.f. stages and we now proceed t o the f ront
end.
10. Before making a ny adj ustments her e,
see that the pointer sweeps the dial scale
properly_ 11. Remove the hot leael of the
signal gener ator from the mixer gr id and
loosely couple to the antenna terminal of
the r eceiver through a 3-J.tJ.tf capacitor. If
the r eceiver uses a loop antenna and has
no external terminals, place the hot lead
of th e generator close to the loop. In all
~ik.elih.ood , this will provide sufficient signal
lll~ ecbon to enable you to complete the
ahgn m~nt . 12. Remove t he jumper from
t he OSCIllator statol'. 13. Set the r eceiver
I. F.
XFMR
oaa
~\:V~
sc.
05C,
~
~
~
PA DDER
COIL
' F'
R. F.
PA DDER
CO IL
NT'
AN T.
PADDER
0
COI L
ON-OFF
VOLUME
i-I
2
Fig. 1
AUDIO
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AmericanRadioHistory.Com
•
SEPTEMBER, 1958
"tHE
PAGE
Serving the owners of Garrardworld's finest recoo:d plaYing equipmen
and other discriminating listeners
interested. in high fidelity.
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TerrItories otber than U.S.A. and Canada to: Garrard Engineering & Mfg. Co., Ltd. , Swindon, Wilts .• England.
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AmericanRadioHistory.Com
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THREE FULL DAYS OF CONTINUOUS DEMONSTRATIONS
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Sept. 26,27,28
Oct. 10, 11, 12
Oct. 17, 18, 19
Nov. 7,8,9
Nov. 21, 22, 23
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ADMISSION 50¢
RI(iO Enterprises Int. 500 N. Dearborn, Chicago 10, III.
and signa l generator dials to 1400 kc. H.
Adjust the oscillator trimmer for maximum
indication. 15. If your receiver has an oscillator padder or if the oscillator coil i s
sl ug tuned, set the dials to 600 kc aud ad·
just the padder or slug for maximum defl ection. 16. Repeat steps 14 aud 15 until
the dial is correctly calibrated at these
points. 17. Reset both dials to 1400 kc and
adjust all r.f. aud/ or antenna trimmers for
maximum indication on the meter. 18. If
there are adjustment screws, either padders
or slugs, for the low end of the r.f. and
antenn a circuits, r eset the generator and
r eceiver tuning dials to 600 kc and adjust
the r.f. and/ or antenna circuits for maxi·
mum reading. 19. Repeat steps 17 and 18.
More often than not, th e low end cannot
be tracked except by bending stator plates
of the variable capacitor. This tricky business will not be discussed in detail.
Shortwave Bands. No definite method of
aligning these extra bands can be given
here because many of them are tracked at
one point in the center, others at the high
end oniy, and still others, at both ends of
the tuning range under adj ustment.
Some engineers believe that it is best
to align the receiver with a steady d.c.
voltage substituted for the normal a.v.c.
voltage. They hold that, because of the
Miller effect, the receiver will be mis·
aligned when weak signal generator voltages are used, together with the small
amount of a.v.c. voltage which would be
developed under these conditions. The d.c.
volta ge to be substituted must, therefore,
be made equal to the normal a.v.c. voltage
which wonld be created when r eceiving
strong, local broadcast signals. I do not
subscribe to this view since errors introduced by this method do not become significant until frequencies greatly in excess
of those normally encounter ed in standard
receivers are r eached.
"
Fuses in B Plus
Q. Recently I constructed a pow e?' am plifier. It is conventional in design, except
that, as an added safety measure, I included a fuse in tile B pl~ts lead, as well as
fuses in each side of the a.c. line leading
to the primary of t he power tmnsf01'me?""
The f~bse in the B pllbS circlbit is always
burning out when the equipment is turned
off. This is particlblarly strange when you
realize t hat the current rating of the flbse
is sufficient to handle the C1b1"1"ent drain in
t he amplijie"r, and that the 1tnit is a Fuset?'on, designed to take m07lwntary ove?'loads. Why sh01bld th ese f1Lses blow? Vic tor Vine, Canandaigua, N. Y.
A. The following explanation is at least
partially correct, but befor e assuming its
correctness, make doubly snre about the
amount of current drawn from the power
supply. If it is more than the current rating of the fuse, it won't take much surge
current to blow it. Finally, be sure to see
whether the B current exceeds the combined drain of all the tubes pIns that of
any bleeders which are present in the circuit. If it does, you mnst find the reason
for this extra drain.
Assuming everything is operating normally, the fuses go as a r esult of the
following :
(Contimbed on page 48 )
AUDIO
4
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•
SEPTEMBER, 1958
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AUDIO
•
5
SEPTEMBER, 1958
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LETTERS
Who Hea rs 20 cps?
Sm :
As r egards your question "Who hears 20
cps ~ " th e answer is, of course, "Nobody";
but the point about testing speakers at this
f r equency is that those that cannot be
heard are always the best. In other words,
a poor speaker makes a very nasty noise at
20 cps, and this is one of the quickest ways
of assessing the low-frequency performance
of a unit or enclosure.
I am sure you do not want another letter
from me to appear in your journal this
year, but if you could find room just to
refer to this explanation I should be much
obliged.
G. A. BRIGGS,
Wharfedale Wireless Works Ltd.,
Idle-Bradford,
Yorkshire, England.
( He may be so S~tre ab01tt his letters, b ~tt
we a1·en't. We Wee 'em. ED.)
The Turntable That Changes Records
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Stereo Source on Mono Chan nel
Sm:
I have been hearing FM broadcasts of
stereophonic tape on a monophonic FM
station with usually magnificent r esults. I
assume th ey are mixing the two channels.
If: the r ep r od uction result ing from this
method is superior to monophonic tapes,
ca nnot this method of using stereo tapes or
discs be ex tended to home use~ Do you
agree that playing both channels of a stereo
t a pe monophonically is superior to the same
I'ecording ou monophouic tape ' If so, would
you consider this a stepping stone whereby
existing monophonic equipment cau be
utilized for the present ~ Assnming my con clusions have some validity, I feel thnt
many enthusiasts would be more willing to
take the first step toward stereo if some
improvement in r esults from their present
equipment co uld be anticipated.
J. PUSHKIN,
241 Front St ..
H empstead, N. Y.
(Mixing both st el'eo tmcks into one channel
sl101tld not necessarily be bettel' than a
good monophonic l'ec01'ding, since 'it wO~tld
imply mixing bot h ?nicrophones together.
Stereo mike pi()k-~tp tecllnif11le is ?1l,ore de'I1wnding , however, and perhaps bett er overall res~t lts might be ootained in that mannel·. At least, a good stel'en nic/c np- con'IMcted to cancel O~/,t ve?·tical sionals (.~ee
page 38) -and f ed to a single channel
W01t ld not damage ste'l'eo 'I'ecords, .~o we
wou,ld s~tggest the change to a stereo pickup
as the fir st step toward a conversion. ED.)
Kays and Emms
SIR:
In yo ur EDl'fOR'S HE VIEW in Julv you
r efer to th e use of "K" as shorthand 'for
1000 and ask for com ments.
Here ar e mine.
There is llotbing imprecise about using
K fol' 1000. It co mes f rom the French word
Kilo meaning 1000 and is well known in
the Kilom eter and th e Kilogram.
If two ca thode resistors are described as
130000 and 1.3Koo respectively, they have
(in theory ) exactly th e same value-on e
i ~ neither more nor less than the other. Is
thel'efore quite propel' to use the symbol
as an a bbl'e,7iation for 1000, and it may
well be nsed with any resistance value
a bove 99900 and below 1 Meg.
From this, it is quite correct to describe
a resistor of 270,00000 as 270Koo. There is
6
www.americanradiohistory.com
AmericanRadioHistory.Com
nothing wrong in describing it as 0.2 7Mol
instead, if preferred,
.
The ,niter, being an old tUller, tends to
think of grid leaks in terms of Megs, Tl~ e
modern equivalent of the 14 -Meg, leak IS
a 0.27-Moo resistor. Anode and screen resistors he thinks of in terms of t housand s
of ohms, and so, in a single diagl'am he
might describe a 270,000-00 scree n r eSIsto r
as 270 Koo while a similar resistor used as
a grid leak might be described as 0.27. Moo,
Inconsisten U Well, p erhaps, but WIth a
r eason and neither is wrong.
On occasion the writer teaches electronics
and so h as t he duty of presenting con cepts
to the students in the way which will be
beneficial to them. Since th e use of K for
1000 is well established and internation ally
accepted, t hey are bound to Jllee~ it ~on­
tinuously during their (electrOlllC ) ltves
and so they are t aught about it ,an.d use, it
right from t he sta rt, After all, It ts. eaSIer
to write 47 Koo for an anode reSIstance
than 47,00000.
At an inteJ'Jlational convention about 20
years ago or more, it was decided to drop
the nsage of "M" as a symbol for 1000,
r eserving it for Meg, and to use ~h e K for
1000. One is still likely to bump ll1to compouents on the continent of Europe, p articnlarly on very old sets, in which. the ,M
stands fol' 1000 instead of havmg ItS
present day meaning of 1,000,000. It is
therefore always necessary to warn students
about this trap, which with time shoul rl
become r ar er and r arer,
p, G, A. H, VOIG'!',
31 High P ark Gard en ,
Toronto 3, Canada .
Sm:
,
I want to make a point for the use of
rational abbreviations, In the metric syst em, decimal p arts and. multiples ar e
named, as in the followll1g tables. In
normal usage, only those powers of ten. ~re
pl'eferred that have as exponent a ,PosltiV,e
or negative multiple of th~ee, as: kilo = 10" ,
micro =10-6 , For all practIcal purposes, th e
list reduced for resistors to milli, kilo, and
mega, and for capacitors to micro and pico.
Using these prefixes, v3;lues can. be
printed in wiring diagrams WIthout decUllal
points, as : 4k7 for 4.7koo ; 2M3 for 2.3
Moo and 220k (not: M22!) for 0.22 Moo.
This system is 'used, in many ~uropeall
countries without creatmg confUSIOn and I
can see no reason why it could not be
adopted here more generally and thus bring
clarity where inconfori:nity abounds,
A, VAN ROGGEN,
2 Ravine Road,
Wilmington 3, Delaware.
(Substituting the letter.tor .the decimal
point wmtld seem to c ~anfY dWflrams ?-nd
printed 7naterial wheretn the dect~nal pOtnts
occasionally get lost, Hop e thts can be
standardized. Also, we prefer "Pt" to t ll e
'I1tore bu lky "'/L/Lt" b~tt it isn't usual in U.S .
p~t blications, ED.)
PREFIXES
PREF ERRED
Va lue Name
10-'2
10-·
10-·
10-3
10 3
10·
10·
10 12
Prefix
p ico
nano
m ic ro
m ill i
ki lo
mega
giga
te ra
n
/L
m
k
M
G
AUDIO
•
P
OTHER
Va lue
Na me
10-2
10-"
10
10'
centi
deci
deca
hecto
Prefix
c
d
D
h
T
SEPTEMBER, 1958
stereo
tape deck kit
M~~~~~~~D
stereo equipDlent
cabinet kit
$149 95
95
SPEAKER WING MODEL SC-1L or R $39
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$143 95
CENTER SECTION MODEL SE-1
Enjoy the wonder of Stereophonic sound in
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preamplifier. Features include two printed circuit board s-l ow noise EF·86 tubes in
input stages- mic and hi-level inputs- push-pull bias-e rase oscillator for lowest noi se
level-two cathode fo ll ower outputs, one for eac h ste reo channel-output switch for
instantaneous monitoring from tape wh ile recordin g. VU meter and pause control for
ed iting. Tape spe~ d s 3Yo and 7~IPS. Frequency response ±2 db 40·12,000 CPS at 7Y,
IPS. Wow and flutter less than .3%. Signa l-to-noise 55 db at less than 1% tota l harmo ni c
distortion. NARTB playback equa li zation. Make you r own hi gh quality recordin gs for
many pl easant li stening hours.
Beautifully designed, this ste reo equipment cabinet has'
ample room provided for an AM-FM tuner-tape deck
- preamplifier - ampli fiers - record change r - record storage an d speakers. Constructed of YoN soli dcore Philippin e mahogany or se lect birch plywood ,
beautifully grained. Top ha s shaped edge and sliding
top panel. Sliding doors for front access. Mounting
panel s are suppl ied cut to fit Heat hkit units with extra
blank panels for mounting' your own equipment. Easyto-assemble, all parts are precu t an d predrilled. Includes all hardware, g lue, legs, etc. an d detailed in-.
struction manual. Speaker wings and center unit can
be purchased separately if desired. Ove rall dimensions
with wings 82 W. x 31' H. x 20 D. Send for free details.
N
STEREO PREAMPLIFIER KIT
DELUXE AM-FM
TUNER KIT
HEATHKIT
MODEL PT-1
HEATHKIT
MODEL SP-2
Here is a deluxe combination
AM-FM tun er with all t he advanced desig n features requ ired
by the critical listene r. Id eal for
ste reo app lications sin ce AM
an d FM ci rcuits are separate and
individually tuned. The 16-tube
tuner uses three circuit boards
for easy asse mbl y. Prewired and
preali gned FM front en d. AFC
wit h on /off sw it c h-fl ywhee l
tunin g and tunin g meter.
$56 95
Thi s unique two-channel control ce nter provi des all control s
necessary in ste reo applications.
Bu ild in g block design lets you
buy basic sin gle channel now
and ad d secon d snap- in channe l
late r f or stereo without rewiring.
12 ' inputs each with leve l con trol-NARTB tape equali zation
- 6 dual concentric controls in c lu"ding loudne ss co ntrol sbuilt·in power suppl y.
55 WATT HI-FI
AMPLIFIER KIT
HEATHKIT
MODEL W-7M
$5495
First ti me ever offe red - a 55 watt basic hi-fi amplifi er fo r $1
pe r watt. Features EL-34 pu shpull output tubes. Frequency response 20 CPS to 20 KC with
less than 2% harmonic distortion at full output throughout thi s
range. Input level control and
" on -off" switch provided on
front pan el. Unity or maximum
dampi ng factors for all 4, 8 or 16
ohm speakers.
N
12 WATT HI-FI
AMPLIFIER KIT
HEATHKIT
MODEL UA-1
Ideal for ste reo applications, this
12-watt powe r package represe nts an outsta ndin g dollar
va lue. Uses 6BQ5 / EL84 pushpu ll output tubes . Less than 2%
total h ar moni c disto rt ion
throughout the entire aud io
range (20 to 20,000 CPS) ilt full
12·watt output. Designed for use
wit h preamplifier models WAP2 or SP-1. Taps for 4, 8 and 16
ohm speake rs.
For co:mplete infor:mation on above kits-Send for FREE FLYER.
HEATH COMPANY •
AUDIO
•
a
SUbSidiary~~ystrom,
Inc. •
Benton Harbor 25, Mich.
7
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
easy-to-build
high quality
Look ... how simply yo u can
asse mb le your very own high fide lity
system! Fun-fill ed hours of share d
pleasure, and an everl asting sen se
of personal accompl ishment are
just a fe w of t he re ward s. Heathkits
cost you only HALF as much as
ordi nary eq ui pment and t he quality
is unexcell ed. Let us show you
how easy it really is ! ...
Step-by-Step
Assexnbly
Instructions _
Read the step ...
perform the operation
. . . and check it offit's just t haI simp le l
These plainl y·worded,
easy·to·foll ow steps
cover every assembly
operation.
Easy-to-follow
Pictorial
Diagraxns . . .
Detail ed pictoria l
diag rams in you r Heat hkit
construction ma nual
show w here each and
every wi re and pa rt is
to be placed.
Learn - by- doing
Experience
For All Ages ..
Kit constru cti on is not
only fun-but it is
educationa l too l You
learn about radio,
electroni c parts and
circuits as you bu il d
your own equipment.
Top QualityNaxne-Brand
Coxnponents
Used in All Kits . ..
HEATHKIT
bookshelf 12-watt
aDlplifier kit r"~~~:~'E~'-:"'~ -
NEW
• • •
• • • !" • • • • • • • • • •
The re are many reasons why this attractive amp li fier is a t remendous do ll ar va lue. You get many extras not ex pected at this
pri ce leve l. Ri ch, f ull range, hi gh fide lity sou nd rep rod ucti on
wit h low disto rtio n and noise ... plus "mode rn" sty ling , making it suitable fo r use in the open, on a bookcase . or end table.
Look at t he feat ures offe red by the mode l EA-2 : fu ll range f requency response (20- 20,000 CPS ± 1 db) wit h less than 1%
distortion over this range at fu ll 12 watt output-i ts own bui lt- in
preamp lifie r wit h provision fo r three separate i nputs, mag
phono, crystal phono, and tuner- RIAA equalization-separate
bass and treble tone controls- special hum control-and it's
easy-to-build . Complete instructions and pictorial diagra ms
show where eve ry part goes. Cab inet shell has smooth leat her
textu re in black with i nlaid gold design . Front panel featu res
brushed gold tri m and buff knobs with gold inserts. For a rea l
sound thri ll the EA-2 wi ll more than meet your expectations.
Shpg. Wt. 15 Ibs.
El ect ronic compone nts
used in Heathkits come
from we ll -known manufactu rers with esta blished
reputations. You r
assu rance of Jong life
and troub le·free service.
8
TIME PAYMENTS AVAILABLE
ON ALL HEATHKITS
WRITE FOR FULL DETAILS
AUDIO
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•
SEPTEMBER, 1958
chairside enclosure kit
NEW
This beautiful equipment enclosure will
make your hi -fi system as attractive as any
factory-built profess ionally-f inished unit. Smartl y designed for maximum fle xibility and compactness consistent with attractive appearance, this enclosu re is intended to house the AM and FM tuners
(BC-1 A and FM-3A) and the WA-P2 preamplifier, along with the
majority of record cha ngers, wh ich wi ll fit in t he space provided .
Adequate space is also provided for any of the Heathkit amp lifiers
designed to operate with the WA -P2. Durin g co nstruction the tilt-out
shelf and lift-top lid ca n be install ed on either right or left side as desired. Cabinet is co nstru cted of sturdy, ve neer-surfaced furnituregrade plywood X" and %" thick. All parts are precut and predrilled
fo r easy assembly. Contemporary available in birch or mahogany,
traditional in mahogany only. Beautiful hardware supplied to match
each style. Di mens ions are 18" W x 24" H x 35X " D. Shpg. Wt. 46 Ibs.
CONTEMPORARY
CE-1T Mahogany
Be sure to specify
model you prefer
TRADITIONAL
HEATHKIT
HEATHKIT
high fidelity FM tuner kit
broadband ·AM tuner kit
For noise and static free sound reception, this FM tuner is you r least
expensive source of hi g h fidelity material. Efficie nt ci rcuit design
features stablized oscillator ci rcu it to eliminate drift after wa rm-up
an d broadband IF ci rcuits assu re full fidelity with high sensitivity. All
tunable component s are prealigned so it is ready for ope ration as soon
as constru ction is comp leted . The edge-illuminated slid e rul e dial is
clearl y numbered for· easy tu ning . Covers comp lete FM band from
88 to 108 mc. Shpg. WI. 8 Ibs.
Thi s tuner differs from an ordina ry AM radio i n that it has been designed especia ll y for high fidelity. A special detector is incorporated
and the IF circu its are "broadbanded" for low sig nal distortion. Sensitivity and se lectivity are excellent and quiet performance is assured
by a hi gh sig nal·to-noise ratio. A ll tunable components are preali gned
before shipment. In corpo rates automatic volume contro l, two outputs,
and two antenna inputs. An edge- li g hted g lass slide rule dia l allows
easy tuning. You r "best buy" in an AM tuner. Shpg. Wt. 9 Ibs.
MODEL FM-3A $26.95 (with cabinet)
MODEL BC-1A $26.95 (vvith cabinet)
HEATHKIT
rnaster control prearnplifier kit
Designed as the "master control" for use with any of the Heathkit
Williamson-type amplifiers, the WA-P2 provides th e necessary compe nsati on, tone, and volume co ntrols to properly am plify and condition a
signal before sendi ng it to th e amp lifier. Extend ed frequency response of
± 1X db from 15 to 35,000 CPS will do full justice to the finest program
material. Features eq uali zation for LP, RIAA, AES, and early 78 records.
Five switch-selected inputs with separate level controls. Separate bass
and treble co ntrols , and vo lume co ntrol on front pan el. Very attractively
styl ed, and an excepti onal dollar va lu e. Shpg . Wt. 7 Ibs.
pioneer in
"do-if-yourself"
MODEL WA-P2 $19.75 (with cabinet)
bsidiary of Daystrom, Inc.
electronics
HEATH
AUDIO
•
COMPANY
.
BENTON HARBOR 25, MICHIGAN
9
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
MODEL W-SM
MODEL W-6M
high fidelity aDlplifier kits
To provide you w ith an ampl if ier of top-flig ht performance,
yet at the lowest possibl e cost, Heath has combi ned th e
latest des ign tech niqu es with the highest quality materials
to bring you the W-5M . As a criti cal listener you wi ll thrill
to th e near- distortionless reproduction from one of the
most outstanding high fidelity amp lifi er~ avail able today.
Th e high peak-power handling capabil ities of th e W-5M
guarantee yo u faithful reproduction with any high fide lity
system. The W-5M is a must if you desire quality plu s
economy! Note : Heathkit WA-P2 preamplifier recommended . Shpg . Wt. 31 Ibs.
HEATHKIT DUAL-CHASSIS
MODEL W3-AM
For an amplifier of increased power to keep pace with the
growing capac it ies of you r hig h f id elity system, Heath
provid es yo u with t he Heath kit W-6M . Recog ni zi ng that as
loud speaker systems improve and versatility in record ings
approach a dynami c range close to the co nce rt hall itself,
Heath brin gs to you an amplifier capab le of supplying
pl enty of rese rve powe r wit hout distortion. If you are looking for a high powered amplifier of outstand ing quality,
yet at a price well within your reach , the W-6M is for you!
Note: Heathkit model WA- P2 preamplifier recom mend ed.
Shpg. Wt. 52 Ibs.
HEATHKIT SINGLE -CHASSIS
MODEL W4-AM
high fidelity aDlplifier kits
One of the greatest developments in modern hi -fi reprodu ction was
the adve nt of t he Williamson amplifier circuit. Now Heath offers
you a 20-watt amplifi er incorporating all of the advantages of
Williamson ci rcuit simplicity with a quality of performance consi dered by man y to su rpa ss the origi nal Williamson. Affording you
flexibility in custo m i nstallations, the W3-AM power supp ly and
amp lifie r stages are on sepa rate chassis allowing them to be
mounted side by side or one above the other as you desire. Here
is a low cost amplifie r of ideal ve rsatility. Shpg. WI. 291bs. ,
In hi s sea rc h for the "pe rfect" amp lifier. Williamson brou ght to
t he wo rld a now-famous circuit which, after eight years. sti ll accounts for by fa r the largest percentag e of power amp lif ie rs in use
today. Heat h brin g~ to you in the W4-AM a 20-watt ampli fi er incorporating all the improvements resulting from this unequalled
backg round. Thou san ds of satis fied users of the Heath kit Will iamson-type amplifiers are amazed by its outstand ing performan ce . For many pleasu re -fi ll ed hours of li steni ng enjoyment
this Heat hkit is hard to beat. Shpg. Wt. 2S Ibs.
HEATHKIT
HEATHKIT
high fidelity
a:mplifier kit
electronic
crossover kit
MODEL A-9C
MODEL XO-1
For maxim um performance and versatility at t he lowest
possibl e cost the Heathkit model A-9C 20-watt aud io
amplifier offe rs you a -trem endous hj-fi value. Whether fo r
your home installation or publ ic address requirements
this powe r-pa cked kit answers eve ry need and conta ins
many features unusual in instruments of this price rang e.
The preamplifier, main amplifier and power su ppl y are all
on one chass is pro viding a very compact and economical
package. A very inexpensi ve way to start you on the road
to true hi -fi enjoyment. Shpg. Wt. 23 Ibs.
One of the most exciting improvements you can make in
your hj-fi system is the addition of this Heathkit Crossover
model XO -1 . Thi s unique kit separates high and low frequencies and feeds them through two amplifiers into
separate speakers . Beca use of its location ahead of the
main amplifiers, 1M distortion and matching probl ems are
vi rtually eliminated. Crossover frequencies for each channel are 100, 200, 400, 700, 1200, 2000 and 3500 CPS . Amazing versatility at a moderate cost. Note: Not for use w ith
Heath kit Legato Speaker System. Shpg. Wt. 6 Ibs .
10
AUDIO
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•
SEPTEMBER, 1958
NEW LOW PRICE!
"LEGATO"
high fidelity speaker systenl kit
Wrap you rself in a blanket of high fidelity music in its true form. Thrill to
sparkling treble tones, rich, resonant bass cho rd s or the spine-tingl in g
clash of percussion instruments in this masterpiece of sound reproduction . In the creation of the Legato no stone has b'ee n left untLJrned to bring
you near-perfection in performance and sheer beauty of style. Th e secret
of the Legato' s phenomenal success is its, unique balance of sound. The
carefu l phasing of high and low frequency drivers takes you on a melodic
toboggan ride from the heights of 20,000 CPS into the lo w 20's without the
slightest bump or fade along the way. Th e elegant simplicity of style wi ll
complement your furnishings in any part of the home. No electronic knowhow, no woodwo rking experience required for construction. Just follow
clearly illustrated step-by-step instructions. We are proud to present th e
Legato-we know you will be proud to own it! Shpg . Wt. 195 Ibs.
HEATHKIT
BASIC RANGE
I
....................
.
...
MODEL HH-l-C
(imported white birch)
MODEL HH-l-CM
(African mahogany)
., ................... ... ..
HEATHKIT
RANGE EXTENDING
high fidelity speaker system. kits
MODEL
$3995
Designed to supply very high and
very low frequencies to fill out the
response of the basic (SS-1)
speaker, this speaker system extends the range of your listening
~~~~L
pleasure to practically the entire
range of the audio sGale. Giving the appearance of a single
piece of furniture the two speakers together provide a superbly integrated four speaker system. Impedance 16 ohms.
Shpg. Wt. 80 Ibs.
A truly outstanding performer for its
size, the Heathkit model SS-2 provides
you with an excellent basic high fidelity speaker system. The
use of an 8N mid-range woofer and a high frequency speaker
with flared horn enclosed in an especially designed cabinet
allows you to enjoy a quality instrument at a very low cost.
Can be used with the Heathkit "range extending" (SS-1B)
speaker system. Easily assembled cabinet is made of veneersurfaced furniture-grade X plywood. Impedance 16 ohms.
Shpg. Wt. 25 Ibs.
55-2
$99 95
N
FrfJfJ
Catalog!
HEATH
D~bSidiary of Daystrom, Inc_
pioneer in
"do-it-yourself"
electronics
Don't deprive yourself of
the thrill of high fidelity or
the pleasure of building
you r own equipment any
longer. Our free catalog
li sts au r enti re Ii ne of kits
with complete schematics
and specifications.
Send for it today!
COMPANY. BENTON HARBOR 25, MICHIGAN
o Please send the Free HEATHKIT catalog.
o Enclosed is 25c for the New HI-FI book.
name
address
city &. state
ALSO SEND THE FOLLOWING KITS-
NEW! "DOWN-TO-EARTH"
- HIGH FI"DELITYBOOK
MODEL NO.
ITEM
QUANTITY
PRICE
THE HOW AND WHY OF HIGH FIDEL-
ITY, by Milton Sleeper, explains what high
fidelity is, and how you can se lect and plan
your own system. This liberally-illu strated.
48-page book tells you the HI·FI
story without fancy tec hnical
iargon or high-sounding t erminology.
AUDIO
•
25 C
Enclosed find
$ ...............
Please enclose postage for pa rcel post- ex press orders are shipped deli very
ch arg es coll ect. All prices F.O.B. Benton Harbor, Mich. NOTE:
subject to change without notice.
_________________________________________________
J
P~ices
11
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
ere.
edward litnall Canby
1. CROSSTALK TALK.
Perhaps it's just as well that the new
stereo tape magazine is taking its time
about a public appearance. A good many
of us have been fully occupied with the
stereo disc, which finally became a commercial reality in force along in the middle of the summer. The problems inevitable
ill the first splurge of real, down-to-earth,
practical disc stereo (as distinguished from
advance hoopla, rosy demonstrations, tests,
samples and so on) are now showing up
and will continue to show up-I'll make
a good guess-for at least a solid year
before we reach the semblance of an even
keel. It took a lot longer t han that, remember, to stabilize the original LP development. More of this shortly. Meanwhile, back to the still· existing vacuum
that is the stereo tape magazine.
The RCA Victor tape 'rnagazine-I hereby
adopt that term for good, in place of the
wholly confusing "cartridge"-was originally announced for release in June, more
01' less. My last unofficial checkup turned
up the interesting thought (from sources
usually reliable, etc., etc.) that the first of
the stereo tape magazines would surely be
in the stores somewhat after publication
of this issue, in mid-September I The first
magazine tape machines from RCA, on
which to play the new tapes, are scheduled
to make a nebulous debut at this point;
I gather only that by Christmas time you'll
be able to give the kiddies a magazine t ape
stereo record player without t oo much buying trouble. (Of course there are others
than RCA Victor likely to offer tape maga·
zine players in the near future; they may
actually beat RCA to it.)
During the summer there were several
repeat RCA Victor demonstrations, follow·
ing up the excellent one that occurred in
late May, as reported here in the July
issue. There were only a few, I understand,
because the tape player was constantly being shuttled back and forth from place to
place and so was out of act.ion, or elsewhere, most of the tim·e.
Yep, I mean just that. The best of my
guess is that there was exactly one RCA
Victor tape magazine player in semi-pUblic
action during most of the summer. Commercial production of the product wasn't
yet under way.
Now don't go jumping to wrong conclusions. I am not implying that there has
been more than perfectly normal and expected launching trouble in the magazine
tape project. I am not implying that things
have gone wrong, in any but the usual
minor and irritating ways. It's for this
very reason that I throw out the above
casual information.
What I mean is-do not allow the pres·
ent slow-motion appearance of magazine
tape to fool you into underestimating its
coming importance and coming valnes. I'll
stand by all 1 said in the July issue, perhaps even more strongly now, though no
major new information has appeared since
the first big publicity break and the stuff
is still not available, at this writing, for
home trial in person. What I wrote was,
shall I say, interpretive speculation,
based on the available information as released to the press and on brief press
demonstration. What little I have learned
indirectly since then has only bolstered me
in my conclusions.
In this connection, I had an interesting
letter from an Ampex official. (The fourtrack tape system is a joint enterprise involving both Ampex and RCA.) This official, who is on the inside, was "a little
more than slightly disturbed"-as he put
it-by the fact that I raised the question
of possible cross-effects between the four
challlleis on the new tape. There is none,
he says, and descdbes his own Ampex
demonstrations to the public, which I
wasn't ab le to heal' myself. He also gives
technical reasons why there should be none,
which I'll get to in a moment, since the
idea is certainly interesting to all of us
who work or play with magnetic tape.
I'll only suggest, for my own record,
that I did raise thl! question of possible
cross-tall{ between the four channels on one
quarter-inch tape simply because it is the
immediate and obvious question that will
jump into any mind, professional or amateur, when the system is first described.
HOU1' tracks, 011 one skimpy little tape ~ No
inter-action between the adjacent channels t
Impossible! That is a lqgical thought, it
seems to me, for anyone who is not directly involved in the highly technical area
of principles and measnrements and performances that are involved.
I snggested, rather circumspectly, that
I didn't hea1' any cross-talk at the RCA
Victor demonstration. That was at least a
statement of fact, in the midst of a lot of
speculation! I also suggested that neither
RCA nor Ampex would be likely to embroil
their respective reputations in a tape system where such an objectionable fault as
this might occur ill pmctice. The Ampex
official-I'll omit his name merely to keep
things for the time being on a plane of
generalities-reiterated this idea, which I
find thoroughly sound. Frankly, I think you
can trust both RCA and Ampex not to have
got themselves too far into a technical booboo in fundamental respects.
Barring a few inevitable preliminary
bugs which we can expect as normal, the
fo ur·track magazine system will work,
will work well, and will satisfy its "most
discriminating" users, as the. old phrase
used to go. Not everybody-Heaven forbid.
There are still lots of people who stick by
the 78 as the best record (in its hi-fi microgroove form-I'd go along with that, too,
aside from the little matter of practicality)
and who like to play their tape at 15
inches, or 30, for super perfection. But if
12
you'll admit that some of the standard LP
records are quite satisfactory and that at
least a few 7! ips commercial tapes are
pretty good, then you will have no cause
to expect less from the coming 3il ips
tapes. 'l'hat's my expectation. I can't say
more, because I haven't done any firsthand home testing.
As to that cross-talk matter, Ampex
points out a factor that I didn't know
about and, I suspect, many tape users
would not know about either. I'll quote
directly from Mr. - --'s letter.
"It is not the proximity of the various
tracks on the tape itself [that causes tape
cross-talk between challllels]. Cross-talk is
a transformer coupling phenomenon between the windings on adjacent head
stacks. In fact, in this new four-b'ack system we have better isolation between channels than we have ever enjoyed in any pre·
vious type of equipment. This is because
the tracks are narrower and the spacing
between the heads is farther apart by one
whole track width, thus allowing for more
shielding between the heads."
"The RCA statement that cross talk just
doesn't exist is correct.... This is no trick·
ery; it is just good design. In fact, the
technique of gaining the hitherto unlleardof quality which we have been able to come
up with on 3il ips tape we consider to be a
significant contribution to the art." That's
just what I said, in July, you'll note.
In the space between the four dots,
above, Ampex describes demonstrations of
the system back in April for the recording
companies, at which this question of crosstalk came up. The four-track tape, modulated on all four tracks, was pushed sidewise by hand on the heads, to prove that
tlJere was, indeed, sound recorded in both
directions-that the two tracks not being
played were silent until the tape was
pushed off its proper alignment. I didn't
hear this demonstration, again, but I don't
doubt that it happened.
I think the points to note well, in the
above account of cross-talk, are that it is
not on the tape itself that cross·effects oc·
cur, but in the heads, after the signals have
been picked up, and furthermore, that there
is more space between playing tracks in
this system than in the more conventional
two-track system.
It would seem to me-speculating again
-that this focusses the problem very
nicely, on (a) stacked-head design and (b)
mechanical alignment of tape motion. As
to the first, Ampex would seem to have
clinched the matter neatly as far as an
outsider is concerned. There is more shielding possible between heads here than in
the two·track system, due to the oppositedirection track that takes up space between
each pair of tracks in use. Remember (to
be simple-minded) that we never play all
four tracks at once-there is always a
blank or unused track next to a track in
use. In the head configuratiou, this space
can be given over to shielding. If crosstalk originates in the heads themselves,
then Ampex certainly has a point very well
taken.
As to the second point, mechanical tape
alignment, I'm not quite so sure. I am
sure as far as Ampex equipment is concerned. Obviously, Ampex will make its
equipment so that the tape is held to accurate motion, minus any sort of side·play
that might accidentally bring a piece of a
wrong track-even a tiny fringe-under a
playing head. I am reasonably confident
that the RCA Victor equipment, on a lower
price scale, will have lie-ked this problem
in principle, and pl'obably in practice too,
even at the begilllling. But it is a problem.
Professional equipment for making com(Continu ed 011 lJage 80)
AUDIO
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•
SEPTEMBER, 1958
" Rooms 338 and 342, 1958 N. Y. Hi Fi Show"
AND
MONAURAL
FM Tuner HFT90
Stereo
Amplifier-Preamp
HFBI
Bookshelf
Speaker System
HFSI
Speaker System- HFS2
36" H x 151/4" W x 11112" 0
NEW STEREOPHONIC EQUIPMENT
HF85: Stereo Dual Preamplifer is a compl et e stereo
control system in " low silhou ette" design adaptable to
any t ype of installation . Sel ects , preamplifies, control s
any stereo source-tape, discs, broadcasts. Superb variable cro ssover, feedback tone controls driven by feed back amplifier pai rs in each channel. Distortion borders
on unmeasurable even at high output level s. Separate
lo-Ievel input in each chann el for mag . phono, tape head,
mi ke . Separate hi-level inputs for AM & FM tuners &
FM Multiplex . On e eac h au xiliary A & B input in each
channel. Independent level, bass & treble con trols in
each channel may be operated to gether with built-in
clutch . Switched·in loudn ess compensator. Function
Selector permits hearing ea ch st ereo channel individually, and reversing th em; also us e of unit for stereo or
monophon ic play. FUll-wave rectifier tube power supply.
5-12AX7/ ECC83, 1·6X4 . Work s with any 2 high-quality
po we r am plifiers such as EICO, HF14, HF22, HF30, HF35,
HF50, HF60 . Kit $39.95. Wired $64.95 . Includes cover.
HF81: Stereo Dual Amplifier-Preamplifier se lects,
al11plifies & control s any ster eo source - tape , di scs,
broadca sts-& fe eds it thru self-contained dual 14W amplifiers to a pair of speakers. Monophonically: 28 watts
for yo ur sp eakers ; complete stereo preamp . Ganged level
controls , separate focu s (balance) control , ind epend ent
full-range bass & tr eble control s for each ch annel.
Id enti cal Willi amson·type, push-pull EL84 power amplifi ers, excell ent output transform ers. " Service Selector"
sw itch permits on e preamp·control section to drive th e
intern al powe r amplifi ers while other preamp.control
section is left free to dr ive your ex isting externa l ampli.
fi er. Kit $69 .95. Wired $109.95 . In cl. cov er.
MONAURAL PREAMPLIFIERS (stack 2 for Stereo)
NEW HF65: superb new design , Inputs for tap e head,
microphon e, mag-phon a cartrid ge & hi -level sources. 1M
distortion 0.04% @ 2V out. Attracti ve " low silhouette"
des ign. HF65A Kit $29 .95, Wired $44.95. HF65 (with powe r
supply) Kit $33 .95. Wired $49 .95 .
HF61: " Rivals the most expensive preamps " - Marshall,
AUDIOCRAFT. HF61A Kit $24 .95, Wir ed $37.95, HF61 (wi th
powe r supply) Kit $29.95. Wired $44.95.
MONAURAL POWER AMPLIFIERS
(use 2 for STEREO)
HF60: 60-Watt Ultra Linear Power Amplifier with
Acro TO -330 Output Xfmr .; "One of the best-performing
amplifiers extant; an excellent buy." AUDIOCRAFT Kit
Report. Kit $72.95. Wired $99 .95 . Cove r E-2 $4.50 .
HF50: 50-Watt Ultra Linear Power Amplifier with
ex tremely hig h quality ' Chi cago St and ard Output Tran sf orm er. Id entical in eve ry oth er r espect to HFSO, same
specs at 50W. Kit $57 .95. Wired $87 .95. Cove r E-2 $4 .50.
NEW HF35: 35-Watt Ultra-Linear Power Amplifier.
Kit $47 .95. Wired $72.95. Cover E-2 $4.50.
HF30: 30-Watt Power Amplifi er. Kit $39.95. Wired
$62.95. Cover E-3 $3.95.
NEW HF22: 22-Watt Powe r Amplifier_ Kit $38.95.
Wired $61.95. Cover E-2 $4.50 .
NEW HF14: 14-Watt Powe'r Amplifier_ Kit $23 .50.
Wired $41.50. Cover E-S $4.50 .
MONAURAL INTEGRATED AMPLIFIERS
(use 2 for STEREO)
HF52: 50-Watt Integrated Amplifier with complete
"fron t end" fa ciliti es & Chicago St anda rd Output Tran sform er. " Excellent value " -Hirsc h-H ouck Labs. Kit $69.95.
Wired $109.95. Co ver E-I $4.50.
HF32: 30-Watt Integrated Amplif i er. Kit $57.95 _
Wired $89.95. Both includ e cov er.
HF20: 20-Watt Integrated Amplifier. "Well-engineered" - Stockl in, RADIO TV NEWS. Kit $49.95 . Wi red
$79.95 . Cover E-I $4.50.
HF12: 12-Watt Integrated Amplifier. "Packs a
wallop " -POP. ELECTRONIC S. Kit $34.95. Wired $57.95.
SPEAKER SYSTEMS (use 2 for STEREO)
HFS2: Natural bass 30-200 cps via slot-load ed 12-ft.
sp lit coni ca l bass horn . Middl es & lowe r hi ghs: f ront radiati on from 8'12" edge-damped con e. Di stortionl ess spikeshaped super-twee t er radi at es omni-di rec t ionall y. Flat
45-20000 cp s, use ful 30 -40,000 cp s_ IS ohm s. HWD
3S", '15 1f4 " , IJlh " ."Eminently musical ; would suggest
unusual suitabi lity lor stereo. " -H olt , HIGH FIDELITY.
Compl etely f ac t ory-built: Wa lnut or Ma hogany. $139.95 ;
Blonde, $144.95 .
HFSl : Bookshelf Speaker System, co mpl ete wi th f actory-built cabin et. Jensen 8" woo fer, matchin g Jensen
co mpress ion·dri ve r expo nenti al horn t wee t er. Smoot h
cl ean bass ; cri sp ex t end ed hi ghs. 70 -12.000 cp s ran ~e.
CapaC ity 25 w. 8 ohm s. HWD: 11" x 23" x 9". W"m g
tim e 15 min . Pric e $39 .95.
FM TUNER
HFT90: surpa sses wired tun ers up to 3X its co st. Prewired . pre-aligned, t empe ratur e-compensa ted "front end "
- drift-free . Preci sion " eye-tronic" tunin g. Sensit ivity
1.5 uv for 20 db qu ie tin g - SX th at of other kit tun ers.
Response 20-20 ,000 cps ± I db. K-follo we r & multipl ex
ou t puts_ " One of the best buys you can get in high
fidelity ki ts." - AUDIOCRAFT KIT REPORT. Kit $39.95 *.
Wired $65.95 *. Cover $3.95 .
EICO, 33·00 Northern Blvd., L. I. C. 1. N. Y.
A-9
SHOW ME HOW TO SAVE 50 % on 60
models of top - quality equpment as
checked below .
0 Hi-Fi
o Test Instr uments
0 Ham Gear.
Send FREE literature & name of neighborhood EleO dealer.
I
NAME .. .. - ... .... ... .. .......... . . .... - ....... .... .....
I
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AUD IO •
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
EDITOR'S REVIEW
HERE WE GO AGAIN!
of Sep tember , we begin to gird
ourselves in preparation for the hi-fi sho,,spason. As a matter of fact , we rath er enjoy
shows-and there is always a feelin g of being "let
down " after each one of them closes. Unfortunately,
Wf' " 'ill not be able to attend all of them this year
bf'cause there are just too many- eighteen in all
scheduled for th e U. S. during th e months of September , October, and November, and all extending
th l'Ollg-h weekends. Now th er e are only thirteen wf'ekend s in thosp three months, so th f' l"f' are naturally some
dupli cations-five of the weekends have two shows
each, one weekend has three, and only Albany, Rochest er , New York, Cleveland, and Seattle have weekends all to themselves.
'rhe Institute of High Fidelity Manufacturers has
the New York Show from September 30 to October 4 ;
Philad elphia from October 10 to 12; and Milwaukee
from October 24 to 26 . The Chicago Sho"\o" , run by the
International Sight and Sound Exposition, occupies
the "'eekend of Septemb er 19-21, sharing the days
with Syracuse and its Rigo show. Boston, St . Louis,
and Detroit share October 17 t o 19. Montreal shar es
October 30 to November 1 with Indianapolis, although
Indianapolis starts a day sooner and lasts a day later .
Detroit has two shows scheduled-th e Rigo show from
October 17 to 19 and an ind ep endent group from
November 7 to 9.
....
'l'his is r idiculous. The major shows are costing th e
larger exhibitors from three to five thousand dollars
each, with proportionat ely lower costs in the smaller
shows. Hardly a week passes in the late summer but
what we receive a contract for another shmv with an
invitation to exhibit. But while ,-\Ie would like t o
attend every show ther e is, it finally becomes prohibit ive-and if it is prohibitive to us with relatively little
material to transport around the country, (aud lets
face it, we gen erally ·have nothing left to ship back ) ,
what must it be to those exhibitors who have box after
box of speakers, amplifiers, tape r ecorders, phono
equipment, and so on, to say nothing of a large staff
who must be in attendance.
,Ve are heartily in favor of high fidelity shows-we
should be, since we originated the idea 'way back in
] 949. But we firmly believe th er e should be some
agency which could serve as a "clearing house" fo r
dates, with a more r easonable distribution of locations
and times. '1'0 enable manufacturers to schedule their
p articipation and budget exp enses, it would be desirable to have a deadline for filing show plans f or each
coming season-say, Mar ch 1. Those dates in conflict
could then be ironed out, amicably, we hope, and then
with a definite schedule ahead to plan for, manufacturers could finalize their arrangements with the as-
W
ITH THE FIRST
surance that they wouldn't be r equired to juggle show
plans a half dozen times during the year.
Most advertising is planned in advance for a year
a t a time, and budgets are mad e accordingly . Hi-fl
shows ar e just anoth er form of advertising, and should
be treated the same way .
VI! e still like hi-fi shows, but we would like to see a
little more order in their planning and arrangement.
STEREO M Ul TI PlEX
With the granting of temporary authorization by
the F CC, station WBAI in New York will begin stereo
multiplex broadcast t ests around the first of September. This is a t emporary expedient to p ermit the
st ation to evaluate the en gineering aspects of multiplex
operation as a medium for compatible ster eo broadcasting-her etofore, multiplex operation has been
solely for supplemental services such as backgTound
music, p aging, and so on. 'fhe orig'inal objective of the
Subsidiary Communications Authorizations was to
allow the station to " draw financial sust enance from
them. "
Ther e are at present two opposing camps as to what
the l:j'CC's final rulings should specify for the multiplex operation. One believes that in the inter est s of
optimum Cluality only one sub-channel should be
permitted-and that the sub-channel could be used
eithe1' for stereo broadcasting 01' for background services. 'l'he other contends that a station should be p ermitted to use two sub-channels, allowing for both services simultaneously. Both sides present good arguments
fo r their r espective st ands. Engineering tests of the
degradation of quality r esulting from two sub-channels
a. compared to only one will be studied carefully
before any decision is made by the FCC.
Be that as it may, we will present n ext month the
det ails of an adapter ,vhich will be commercially availabl e within a f ew weeks.
r"
/ ERRATA
Mr. E. F . VlTorthen , author of the article on th e
I sodyn e phase inverter in the August issue, calls ou r
atten tion to two errors in the last column on page 27.
Measured 1M distortion on the amplifier is below .02
pe1' cent at up to 30 watts inst ead of below 0.2 p er cent
- which is rather a big differ en ce. Similarly, the distortion at 45 watts should have been list ed as .06 per
cent, and frequency r esponse ± 0.5 db from 10 to
100,000 cps-which is another big difference. Also, we
note that our own article lists EIi34 's in the parts list
on page 57, instead of the EL84 's that should have
been ther e.
Sorry, but those things do seem to happen.
14
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
•
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
·Bell Laboratories Announces
Pocket-Sized Frequency
Standard for Microwave Systems
Lawrence Koern er, who developed th e portable frequency standard, demon·
strates how th e device can he plugged in at a radio relay station to supply a
checking frequency . Battery-powered, th e device maintains precision cali·
bration for several months.
Inside the portable frequency standard. Four Labora·
tories·develoJJft!d devices make it possjble: (1 ) transistor,
which converts the power from a battery to _radio fre·
quency oscillations; (2 ) voltage reference diode, which
maintains constant voltage; (3 ) piezoelectric crystal unit
of superlative stability; (4 ) thermistor, which corrects
for temperature variations.
Microwave radio relay systems depend critically on the
accuracy of their "carrier" frequencies. At scores of relay stations
along a route, carrier frequenc y oscillators must be checked periodically against a signal from a precise standard.
In the past, the maintenance man has had to obtain his checking frequency by picking up a standard radio signal from a
government station. This operation takes time-and requires
elaborate equipment.
With a new portable frequency standard developed by Bell
Laboratories engineers, the job is much simplified. To check an
oscillator, the portable standard is plugged in, and a button is
pressed. In seconds, it supplies a checking frequency accurate
to one part in a million.
Until now, such precision in a frequency standard has been
obtainable only in a laboratory. The new portable standard makes
. it ava'ilable for routine u se in the Bell System. First use of the
standard will be to maintain frequency control in a new microwave system for telephone and TV, now under development at
Bell Laboratories.
BELL TELEPHONE
WORLD CENTER OF COMM UNICATIONS
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AmericanRadioHistory.Com
LABORATORIES
RESEARCH
AND DEVELOPMENT
A Simplified Control Unit
ROBERT C. CHAPLlCK';'
Believing it is not enough to propose simplicity in an audio system and then
leave it at that, this author follows his own advice and describes a preamplifier
unit designed in accordance with the principles presented some months ago
A
LTHOUGH MANY CIRCUIT diagrams of
preamplifier control units designed
to be built by the user have been
published, none has shown agreement
with the philosophy of system simplicity
proposed by the author ("System Simplicity in Audio," AUDIO, January, 1957).
The object of this paper is to present
further arguments on the a dvantages of
simplification as applied to a reproducing system. Chief advantages are reduction of distortion and improvement of
reliability. Reduction of the number of
parts and of cascaded controls which dup licate each other not only decreases the
distortion but, since reliability is inversely proportional to the number of
parts, improves the reliability.
The philosophy of simplification includes the assumption that the user will
* 10001 McKenney Ave., Silver Spring,
Mel .
HEARING
CONTOUR
COMPENSATOR
¢
Fig . 1. Block diagram of simplified control unit
not experiment with all types of input
equipment but will settle on the best
that he can afford. He will strongly resist the hi-fi dogma that equip ment
purchased at 12 noon is obsolete at 12 :01
P.M. Quantitative and qualitative laboratory tests have shown that most of the
current, better quality phonograph reSWITCH POS ITI ONS
S2
Sl
C20
-t
C2b
R3
R2
12,000·
3900
1 FM/P HONO INPUT
"SCOTCH " 11lA INPUT
"SCOTC H" 190A INPUT
Sl
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117v. A. C.
60 cps
1 -40
- 30
- 20
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PHONS
PHONS
PHON S
PHON S
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HEADPHONES
MUSIC (O PEN) I
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HEARING CONTOUR
COMPEN SATOR
Fig . 2 . Over-all schematic of the author's design fo r a control unit which is effect ive in performance and simple and convenient
to operate
AUDIO
•
17
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
+20
t--
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N ARTB STAN DAR D EQ UALI ZATI ON CURVE _
1"\1- -
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I-- NARTB EQUALI ZATION OF CONTROL UNIT
Fig. 3. Compariso n
Detwee n e quali za t ion p rovided and
t he s t an da r d
N A RT B (R I A Al
curve
1""1'-
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-20
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100
FR EQUENCY
IN
'0000
CYC L ES
PER
SECON D
producers are about equal in excellence.
The same is true for FM tuners using
Armstrong circuits and also for professional-quality tape recorder-reproducers.
The components to be controlled by
the author are a Pickering 370 cartridge,
a Harman-Kardon FM-100 tuner, and
an Ampex 601 tape recorder. The con-
reproducer has an output of 1.228 volts
(+ 4 dbm in 600 ohms) ; and the average
peak output of the tuner, with its gain
control fixed at its maximum position,
is 1 volt at 30 percent signal modulation. A low-impedance output of 0.6
volts is required to drive the 30-watt
power amplifier to half power (this
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Hearing Contour Compensation
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Fig . 4. Re sponse
curve s of hearing
contour compensa to r a t various
se tt ing s.
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•
'0000
10000
1000
FREC UENCY IN CYCLES PER SECO ND
trol unit is to have a minimum number
of controls and adjustments and a fixed
passive network wherever equalization is
needed. In addition, the input signal
should be able to be monitored continuously as a tape record is being made.
The phonograph cartridge has an output of 25 millivolts for a stylus velocity
of 9 centimeters per second; the tape
" SCO TCH" BRAND -
+1
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'"
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allows 3 decibels for overdrive).
With the use of these design p arameters a simple circuit was designed. A
block diagram and an over-all schematic
are presented in Figs. 1 and 2 respectively.
Conventional circuits are used exclusively, so detailed explanations are
not necessary, but descriptions of cer-
190A _
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"SCO TCH" BRAN D- ll1 A _
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,
tain portions are given in following
paragraphs. To minimize the number of
tubes, amplification is based realistically
on actual needs. The amplification factor
for design purposes is the difference between the average maximum voltage of
each source and that needed to operate
the power amplifier.
Essentially, the control unit is a twostage amplifier with two cathode-follower
outputs. Signal sources are mixed by
means of resistive networks which asstu'e
the proper levels. Because each SOUl'ce
has its own power supply, each input
signal is removed by cutting off the
power. Thus, a selector switch is not
needed.
Disc Equalization. Although five equalization curves were formerly advocated,
the RIAA curve has proved to be adequate for all long playing records,
which are used exclusively. An RC network is used to obtain the equalization
curve (Fig. 3). Values are first COlllputed. The circuit is then built and
corrected by component substitution in
conjunction with frequency measurements to give desu:ed equalization.
,
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.
1000
,
.
Fig . 5 . Recordlisten
f requency
respo nse of t ap e
o n Ampex 600
t ape recorde r
'0000
FREQUENCY IN CYC LES PER SECOND
18
A "Hearing Contour Compensator"
is being used with great success in place
of separate bass and treble controls.
Briefly, this Compensator improves the
realism of reproduction by compensating
for the difference in level between the
intensity of the sound of the live orchestra at the recording session and that reproduced at a necessarily lower level in
the living room. It compensates for the
variations in human hearing sensitivity
to sounds of different loudness. Th e
principle of the Compensator is based
on the study of the differences between
Fletcher-Munson curves rather than on
the contotu' of anyone curve. The Compensator is designed to perform in fixed
calibrated steps of 0, - 10, - 20, - 30,
and - 40 phons, where the figures indicate the difference in phons between the
original and reproduced program levels.
The appropriate attenuation is designed
into the Compensator. For speech reproduction a switch is provided to retain
the attenuation but to remove the compensation. Music equalization is completely wrong for speech reproduction
because speech, to provide naturalness,
should be reproduced at about the same
level as the original source, and hearing
contolU' compensation is not needed .
Figtt1'e 4 presents the response curves of
the Hearing Contour Compensator.
When compared with the characteristics
of many commercial controls, these
curves may seem to provide less emphasis to the middle low frequencies. This,
however, is not the case. The Hearing
Contour Compensator does not depart
from the characteristic indicated as
needed by the Fletcher-Munson curves.
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
•
SEPTEMB ER, 1958
Correction for deficiencies in the loudspeaker or any other component does
not enter into the design. The bass response of the selected loudspeaker is adequate. More realistic sound is achieved
by elimination of any booming juke box
effect.
Tape 1·ep1·ocluction. In his program of
system simplicity the author uses only
two types of tape: Scotch InA and
190A, since the tape recorder equalization is set for these tapes. Figu1'e 5
shows the frequency response of the
Amp ex 601 using these tapes. Although
the response using lIlA tape is essentially flat, the 190A tape causes a 5 db
rise above 1000 cps. A loss network,
added to the control unit so that 190A
tape will be reproduced with a flat response, is located at the "tape-FM/
Phono" switch. This switch is necessary
to prevent a feedback loop during ta pe
playback and to permit both wanted and
unwanted program material to be heard
so that undesired signals (such as commercials) can be eliminated. Also, the
original source for a tape r ecord can be
monitored by either headphones or loudspeaker.
Gain Cont1·ol. This control is actually
unnecessary. Acoustic shocks, however,
are avoided by fading in and out the
signal. The operating procedure is to
set the H earing Contour Compensator
to the desired listening level. Th en the
program is brought in by turning the
gain control FULLY clockwise. Thus,
maximum use of the gain control is
realized by full rotation instead of that
portion produced by the 10 pel' cent
rotation common in most volume controls.
Power Supp ly. The power supply is
extremely conventional. No trick circuits
are necessary. An elaborate power supply to produce direct current for the
filaments or the necessity for biasing
the filaments "above ground" is unnecessary through the use of low-noise, nonmicrophonic tubes. The electrolytic capacitors are mounted on the phenolic
wafers supplied, and the holes punched
in the chassis are large enough so the
can will not be grounded. A ground loop
is thus eliminated, reducing the possibility of hum pickup.
MonitM Circuit. During r ecording the
input signal can be monitored continuously by means of the loudsp eaker. However, there are times when headphones
are preferred. An equalizing circuit designed exclusively for the Brush BA-206
headphones is included. This circuit provides a fixed Hearing Contour Compensator and makes the sound from the
headphones as much like the sound from
the loudsp eaker as possible.
Constntction. The location of the various small assemblies is slightly unconventional for home equipment but standard for rack-mounted equipment . The
tubes, electrolytic capacitors, and so on,
AUDI O •
o
Fig. 6. Front v iew
of control uni t.
are mounted on the rear of the chassis,
and the controls ar e on the front p anel.
This design permits mounting the control unit with either a horizontal or
vertical front panel.
Figu1'es 6 and 7 show the front and
rear views of the assembled unit . The
unit with the front p anel opened is
shown in Fig. 8.
The layout for drilling and punching
the !5hassis is shown in Fig. 9. The
dimensions should be followed closely
in order to prevent the small assemblies
•
techniques are employed. All parts are
mounted on the Vector socket turrets,
the electrolytic capacitors,or on switches.
Thus, any small assembly can be replaced
easily and without disturbing any other
assembly.
The best method for assembly is as
follows . All parts are mounted and
soldered onto the Vector socket turrets.
All resistors and capacitors should be
checked to ascertain that the r esistors are
not open and that the capacitors have a
high r esistance. After the turrets are
Fig . 7. Re ar vi ew
of cont rol uni t.
Tubes w ith s hi e lds
from right to le ft
are V!, V2 , and
V3 • Tube in upper
left corner is 6X 4.
from shifting and interfering with each
other.
Some remarks about the p arts are
necessary. Adherence to the suggested
list is urged because all the parts are
chosen from the standpoint of size, tolerances, and proved reliability.
Parts with larger tolerances may be
necessary for tailoring equalizer circuits
exactly; for other uses they are pCl'missible, but many measurements and considerable substitution of parts could be
necessar y to achieve desired r esults. The
parts list also reflects the experience
acquired during the actual construction.
The design of the wiring' is shown in
Fig. 10 and should be followed closely.
The individual parts are located for
minimum hum. Standard telephonic
inside the chassis, substitution of parts
is not particularly easy. Wires do not
have to be wrapped around the terminals
before soldering. Even the U. S. Navy
has accepted finally the fact that solder
has sufficient strength to support parts.
After the turret assemblies are complete,
they are mounted on top (yes, on top)
of the chassis. Now the Vector socket
t urrets are completely wired . This top
of chassis technique, which p rovides
plenty of working room, offers the greatest accessibility and ease of wiring . Although these turrets are handy little
gadgets, once they are loaded with parts
an d mounted within a chassis soldering
at th e tube terminals is very difficult.
Twisted pairs of color coded wires al'e
used prof usely. The color code r emoves
Fig . 8. Con trol uni t
with fron t pane l
ope n. On pane l
f rom left to righ t
are
he adphon e
jack,
t ap e / FM/
phono switch, g ai n
can t r a I, musicvoice switch, hea ring con tour compensator, and pilot
ligh t. Vecto r turre ts
fro m left to ri g ht
a re V!, V2 , a nd Va'
19
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
the necessity for locating the end of a
particular wire with an ohmmeter. A
p air of wires should not be twisted by
grabbing one end and twisting the other.
The prop er method is childishly simple.
Two pieces of wire are cut to the desired
length. One end of each is clamped together in a vise. A wire is grasped in
each hand close to the vise. Then each
wire is twisted clockwise with the fingers.
At the same time the wrists are moved
about each Gther counterclockwise. This
action is repeated until the pair are
twisted together. The twisted pair will
be neat, tight and symmetrical. Describing the action is f ar more awkward than
doing it.
The twisted pairs that go to switches
should be soldered at the Vector socket
only. The filament, plate and ground
leads are laced at this time. The wired
sockets are removed from the top of the
chassis and relocated inside after all
soldered joints have been inspected.
After the remainder of the parts are
mounted on top of the chassis, the power
supply circuits are wired completely and
laced into a cable.
Switches are assembled next . For r eliability all active contacts are wired in
parallel. Most of the resistors and capacitors require their leads to be very
short. Extreme caution should be used
in soldering so that the parts will not
be overheated . An angle bracket (Fig.
9) is used to mount 017 and 018 on S2 '
Switch S 2 and its bracket are mounted to
the front panel and these capacitors ar e
bolted to the inside of the bracket . Resistors R S l and R S6 then complete the comp ensator circuit. The controls, monitor
jack, and pilot light are mounted on the
front p anel. Once the twisted pairs of
wires have been cut to length, the wiring
callI be completed. Lace as indicated. T)lOse
pairs of wires connecting the controls
to the remainder of the circuit should be
long enough so that the front panel can
be opened at least 90 deg. without straining the wires.
Each solder ed joint should be r einspected. The filament and plate leads
are checked for "shorts" to ground. If
the unit passes a mechanical and electrical insp ection, the front panel can be
installed, the tubes and shields inserted,
and the control unit is complete.
Construction of this amplifier was not
without its problems. The proximity of
the Hearing Contour Compensator to the
power supply r esulted in hum caused by
electrostatic coupling. The electrostatic
coupling can be removed by shielding
which, in turn, can be accomplished by
two methods. First and the more difficult
of the two, the compensator switch can
be completely enclosed in a metal box .
In this case the switch r ecommended is
Centralab P A-2002. Second and easiest,
a shield can be mounted on the back of
the switch, in which case Centralab
switch P A-2010 should be used. This
switch has two sections each having two
poles and 2 to 6 positions. The r ear section should be r emoved, and an intersection shield (Centralab catalog P -320)
should be substituted. Although it is not
shown in the photographs, the author
employs the first method.
Observant r eaders will notice some
discr ep ancies between the parts list and
the p arts visible in the photographs. Th e
power transformer shown was employed
because it was available. Unfortunately,
male chassis connectors in the Amphenol
type 80 series are no longer available.
Anyone who wishes to duplicate this
unit will have to employ short cables
with male connectors (J" and J 5 ) for
the outputs.
Resu lts
The first model of the control lmit did
not have input transformer T 2 • However,
the noise level and gain of the first
stage was unsatisfactory. The perform-
FRONT PANE L
HO LE
DI A.
A
3/4
B
%
C
1 5/32
D
Ih
E
%
F
11/ 16
G
3
1 /16
Fi g , 9 . Ch a ssis layol' 1. Sc rew- hole diamete rs for mount ing of pa rts a re left to d iscreti on of bu ilde r. At ri gh t is sho w n bracket
fo r 52'
Al,JDIO •
20
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SEPTE MBER, 1958
ance was improved by the addition of
input transformer T 2 (Chicago Transformer WF-28) in conjunction with
shield SH, (United Transformer shield
A -33). The transformer is mounted between V , and V 2 with the name p late
towards V l ' Then the shield is bolted to
the transformer. During t hese tests considerable variation of hum pickup and
microphonics was discovered in the
EF-86. Therefore, t hree or four EF-86's
should be purchased, and the one least
subject to bum pickup and microphonics
should be used for V , .
The results of the construction of this
control unit have more than compensated
for the expense and time. The disc e:qualization is known to be within ± 2 db of
the standard curve .. A more exact curve
can be obtained by changing values of
R 4 ) R s ) 0 3) and 0 4 , However, the time
involved to get an exact curve is not
justifiable. Background noise is extremely low. With either FM tuner or
disc input the noise is - 61.8 db below
the D.6-volt output. With tape input the
noise is even lower : - 91.7 db below tbe
D.6-volt output. Compensation is pro-
vided for the differences between IllA
and 19DA tape. The Hearing Contour
Compensation is the heart of the unit
and audio system . Greater realism is
achieved since the design is on a more
scientific basis than that which depends
upon the manipulation of bass and treble
controls. The monitor circuit has another
advantage besides being an aid in eliminating commercials. If one 'wishes to
listen late at night without disturbing
anyone, the power amplifier can be
turned off and headphones used exclu(Oontint£ed on page 86)
,--, LACE
V I EF 86
o
I f
f
./-'~
,
'-rri.
LIN E
CORD
REAR
WAFER
Fig. 10. Compl e te w iring diagram of control unit.
AUDIO
•
21
SEPTEMBER, 1958
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Measurement of Amplifier
Internal Impedance
W. H. ANDERSON':'
An analysis of th e possi ble errors wh ich ma y be encountered
with vario us me th ods of measuring output impedance,
and a suggested meth od which minimizes th e errors.
FIFTY-FIVE will probably
go down in automotive history as
"Wraparound Windshield Year."
For similar reasons it will likely be
called "Controlled Damping Year" in
audio circles. While not wishing to get
involved in the controversy as to how
much damping is optimum, it is surely
safe to point out that the source impedance the speaker sees is important
for two reasons:
N
age and it may be almost impossible to
reduce the terminal voltage to one-hali
without encountering error related to
resistance of the leads connecting the
amplifier to its load.
INETEEN
1. It determines the terminal voltage
behavior in the face of inevitable
speaker impedance change accompanying
frequency change.
2. It is the load when the speaker acts
as a generator and releases stored energy.
The determination, on paper, of such
source impedances generally presents
no particular problem . When no feedback is present, the speaker looks back
into the secondary ohmic resistance plus
the resistance transformed down from
the primary. This primary resistance
includes the primary ohmic resistance
plus the a.c. p late resistance of t he
tubes. For instance, Fig. 1 shows two
6V6 triodes (plate resistance about
2000 ohms each) feeding a I3-ohm load.
The source resistance seen by t he load
would be 1.0 + (2 x 2000 + 1000) (13/
13,000) = 6.0 ohms. If negative voltage
feedback alone is present from second*484 Church St., Toronto 5, Ont., Canada.
FEEDBACK
I"
RESI STANC!'
Fig.
1. Ex p e rimental
<:ircuit.
amplifier outpu t
"Backward Driving" Method
Fig.
2.
Consta nt v oltag e
circui t .
eq u iv al e nt
ary back to the amplifier, this 6 ohms
will drop by the same factor as the gain
is reduced by the application of the
feedback. For instance, if the input required when feedback is applied (for
a constant output) is 5.5 times the input required when feedback is absent,
the source impedance will drop to
6/ 5.5 = 1.1 ohms.
If negative current feedback only
were applied, the impedance would
rise but not necessarily by any simple
factor related to gain drop. The catch
is that many feedback circuits are
hard to exactly classify as voltage or
current, negative or positive, and in
such cases calculation is indeed difficult.
Taking a cue from Lord K elvin, the
obvious next step is to attempt a measurement. There seems to be no widely
accepted standard and only two suggested methods could be discovered in
the literature.
The first approach' is, briefly, to
view the output circuit (Fig. 2) as a
constant-voltage source which can be
measured with the load terminals open
circuited-that is, with RL = 00. Then if
RL is dropp ed in value until tbe output
voltage drops to one half the open circuit value, RL must equal R int .
There seem to be two more or less related objections to this approach:
(IA) Since the load seen by the tubes
may vary from a pure inductance to a
very low resistance, the assumption of
constan t voltage, let alone constan t
waveform, is difficult to justify.
(2A) An amplifier with low source
resistance has a very stable output volt-
22
The second method,2 Fig. 3, is to drive
a known current through the output
terminals of the amplifier and ascertain
the voltage drop it produces. There are
two possible objections to this technique:
(IB) If feedback is being taken from
the output terminals in some manner,
care must be taken that the equipment
involved in measurement does not disturb the feedback arrangements.
(2B) If the amplifier is being operated beyond straight class A, the
plate resistances rise as the tubes become cut off for part of each cycle,
(theoretically up to 2.0 times the class
A value when operating Class B) ,s
consequently the source impedances rise
when going from class A to AB to B.
This method would not reveal this
change since there is no signal coming
through the amplifier in the usual way.
It might be possible to run enough
secondary current so that the primary
voltage swing will exceed Ebb of the
stage and in this way simulate normal
op~ration. Thi s would, however, reqUlre an external source of known internal resistance whose power rating
would he at least the damping factor
squared times normal power output of
amplifier under test. In this instance,
FEEDBACK
APPROX.
115 v.
(FROM
VAR IAC)
ABO UT 1.0v.
Fig . 3 . " Ba ckw a rd d riving" m et ho d of
d ete rminin g inte rnal impedance.
AUDIO
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•
SE PTEMBE R, 1958
;:~_l
l lllIlilil'I'.
il l l .1III
2.0
1.5
1.0
IIIIIII1
~!i!!1111111111
7
this would amount to (6/1.1) 2x 4:=1l9
watts. Here again the lower the internal
resistance, the greater the problem in
measuring it.
Fig . 4 . Calculated
internal
impedance for various
values of "R".
10
of distortion as well as the magnitude
of the fund amental.
Figu1'e 4 is an illustration of the
after all did not take into account class
AB operation.
The difficulty with this method (particularly when feedback was on) was
that one was required to read extremely
small voltage variations across the full
load and then divide by the known resistance in both cases in order to find
the current change and, subsequently,
the source resistance. Some streamlining of the procedure may be effected
by using the layout of Fig. 7. By the
use of the voltmeter across the I-ohm
resistor alone, we have the current without further computation, only now it is
necessary to multiply this voltage by the
n umber of ohms total load in order to
find the amplifier terminal voltage in
Examples
A small push-pull triode 6V6GT amplifier of conventional class AB design
was used for a number of tests described.
About 15 db voltage feedback from
the output transformer secondary was
available but could be readily removed
for comparison. The calculated source
impedances were as outlined above-6
ohms without feedback and about 1
ohm with f eedback. With the rated load
of 13 ohms, about 4 watts power output could be obtained with tolerably
small distortion throughout the range
from 40 to 15,000 cps. Naturally, the
power-frequency response was smoother
when feedback 'Was used.
The open circuit/ half voltage method
was tried first. It gave answers that
wel'e almost dead on the calculated
values p1'ovided the level of measurement was kept quite low (a quarter of
a watt or so) otherwise severe squaring
was encountered as the load resistance
was dropped. See (IA), preceding. If
this distortion was disregarded, nearly
any answer one wanted could be produced because the voltmeter reads the
square root of the sum of the squares of
the various frequency components and
the reading is a function of the degree
AMPLIF IER
A.C.
TVM
OUT
Fig . 5 . " Sm a ll increment" method
measuring internal impedance.
AUDIO
•
of
INTERNAL
RES ISTANCE
(OHMS) 15 .0
- - - -1---;/ 4w.
V
12.5
Fig . 6. Internal impedance vs. power
level.
NO
FEEDBACK
-
- - f-- - -
~
7.5
~w.
w.~ 2w.I
5.0
WITH
FEEDBACK
- -/ 2w
10.0
2. 5
I,~w .
o
100
1000
10000
,
FREOUENCY IN CYCLES PER SECOND
point raised in (IB) regarding the Fig.
3 layout. Since the impedance of the
step-down transformer secondary was
negligible, the current metering resistor
R becomes the amplifier load . The magnitude of this resistance is of substantial
importance when feedback is used since
the signal that goes back up the feedback path and is amplified sees the resistor as the load.
'ro get around objection (IA) if one
makes only a small change in the load
r esistance, the internal voliage of the
amplifier should only be slightly affected.
If it then were possible to measure the
small change in output voltage and
divide it by the small challge in current
through the load, the quotient 'Would be
the internal impedance (see Appendix).
Accordingly, the load was changed from
13 to 14 ohms, then from 13 down to
12 ohms (see Fig. 5), the internal impedance computed and the values averaged. Incidentally, the two values in
each pail' were always within ten pel'
cent and usually much closer. This was
done for several power levels, both with
and without feedback and the results
are shown in Fig. 6. Note that at low
power levels the internal impedance
drops down to the computed level, which
each case. The simple advantage of this
layout lies in the fact that with very
low source impedances the output current rises sharply with a drop in load
resistance and since the meter is essentially a
current-measuring device,
greater accuracy can be obtained than
if we were trying to observe a total
voltage change. The values obtained
(Contimwd on page 48)
AMPLIFIER
5
o
Fig. 7. Current m etering for smaIl-increme nt method.
23
SEPTEMBER, 1958
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Stereophonic Recording and
Playback Amplifier
WAYNE B. DENNY :::
Optimum performance may be had with many professional or semi-professional tape decks when employed with the amplifier system described here. Both stereo and monophonic uses are provided.
of stereo records
the present popularity of recorded
stereo tapes can be expected to
diminish somewhat. Certainly the new
discs are more convenient and the cost
differential between the two is considerable. Nevertheless, the amateur recordist
will find it simpler to use tapes for those
cases where excessive duplication is not
required. Although single-channel tape
recorders have found wide public acceptance good two-channel machines are
neither common nor inexpensive. Yet,
the serious amateur can make excellent
stereophonic recordings without undue
financial strain if he is willing to
work out a system employing one of the
several tape-decks currently available
which can be adapted to the p urpose.
One such deck is the V ·i7cing FF75SR
machine and the system to be described
was designed for use with this machine.
Other manufacturers make similar machines which could be used with little
or no modification of the electronics.
In the initial stages of design it was '
found difficult to incorporate both versatility and simplicity into the same system. Admittedly, simple and foolproof
operation is desirable but an analysis of
requirements showed that the inclusion
of a "function switch" (as found in
popular commercial units) would limit
ITR THE ADVENT
W
"Physics Depa?·tment, G?"imnell College,
(}rinnell, Iowa.
RIGHT PLAYBACK AMPLIF IER
PLAYBACK
HEAD
PLAYBACK
OUTPUT
RECORD ING
HEAD
HI -l EVEL
INPUT
HI- LEVEl
INPUT
LOW Z MIC.
HI Z MIC.
MIXED
OUTPUT
B---1
J4
RECORD ING
HEAD
~C=:::j-...J
LEFT RECORDING AMPLIF IER
PLAYBACK
OUTPU T
PLAYBACK
HEAD
Fig. 2 . Insp e ction of t his functional diagram of the recording-playback indicates
that it may b e used for single channel recording and playback, two channel recording and playback, sound-on-sound record ing , tape duplicating, and as a general
purpose preamplifier and mi xe r. Bias supply and electronic level indicators are
not shown.
the usefulness of the amplifier, which is
shown in Fig. 1 . Consequently, a p lugand-jack system of interconnection was
adopted and the experience of several
months has shown t he wisdom of this de-
clslOn. Despite its seeming complexity,
the sophisticated amateur who understands his circuits will find the construction and operation of this unit perfectly
straightforward.
System Philosophy
Fig . 1. Fron t vie w
of ampl if ie r.
24
Although the present recording and
playback amplifier is intended for amateur use this does not imply that quality
of performance is compromised. The
system employs t he usual NARTB
equalization in the recording sections and
the playback amplifiers are adjusted for
:flat response from tapes using the
JARTB characteristic. Noise is minimized by the use of an external power
supply and by employing d.c. on the
heaters of all tubes operating at low
signal levels. Inherent amplifier noise is
below tape noise under conditions of use.
120-cps hum is inau dible.
AUDIO
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•
SEPTEMBER, 1958
r----I
RI7
r-------.--.~MN~~C
R31
r-----~----------~--~~--~C
I
RIGHT PLAYBACK AMPLIFIER
J9
Cl7
R29
I
-1
r-......- - - -.......-------1....._D
I
RIGHT RECORDING AMPLIFIER
r:O~OR__:;:;PL;;;;;-
I
I
RII 2
--- --E
-----i
F
I
I
A
~
.
V I3B"
V I4B
~
I
L _______ ~
R84
RIOO
RI02
R90
.,.,
N
U
I
- - - - - - - - - - - - - -. =--l
LEFT PLA YBAC K AMPLIF IER
R32
I
I
CI6
I
N
'"
I _ _ _ _ _ _ _ -_
tJ _ _ _ _ _ _ _
3 _
" _________
R30
~
~_J
Fig. 3. Schematic diagram of the recording-playback unit. Although several chassis grounds are indicated the circuit is grounded
to the chassis at one point only, preferably near the input jacks. Extreme care must be exercised to avoid ground loops.
AUDIO
•
25
SEPTEMBER, 1958
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AmericanRadioHistory.Com
~;:- . .
"
~~ ~
~-
.
:~
~~;f""'~~"
~~~<-
It -was
desired that recorded material
should be monitored both prior and
subsequent to the actual recording process: switches permit listening comparison between incoming and recorded signals. Recording and playback facilities
are provided in duplicate for single- or
two-channel use. One r ather novel feature of the system is the inclusion of a
hybrid or monitor amplifier whose signal
is derived from both right and left hand
channels at all tittles. This hybrid channel is useful for feeding a "middle" ampliner and speaker: this procedure effectively rids the playback of that "hole in
the middle effect" sometimes experienced
with certain types of speaker placement.
It does. not correct for incorrect speaker
phasing, however.
'l'he system philosophy is best understood by reference to Fig. 2 which shows
the system in block form. Examination
of this diagram serves to indicate the
versatility of the unit. A four-position
JIIixer is provided . With switch 8 5 closed
aH inputs are connected to each recording channel. When 8 5 is open each channel is provided with two inputs for highand low-level signals. Switches 8 9 and 8.
select either the incoming program or the
playback signal for monitoring. The single VU meter is connected to the hybrid
channel at all times. This is a bit unusual and originally some doubts were
entertained about the wisdom of this
arrangement. However, it should be emphasized that separate visual monitoring
of each channel is possible by the inclusion of two electronic level indicators:
these are not shown in Fig. 2 but are
used to indicate approximate recording
level and balance between channels .
The two microphone-input circuits are
alTanged for either high- or low-impedance units. Regular three-wire receptacles are used for balanced low impedance connections. Switching from low to
high impedance is automatic. It will be
noted that several input and output circuits employ paralleled jacks: in each
case one of the jacks is mounted on the
front panel, the oth~r on the rear of the
chassis. The utility of this arrangement
is obvious.
Circuit Details
Inspection of Fig . 3 shows a total of
thirteen tubes not including voltage
regulators and volume indicators. Although the circuit appears somewhat
complicated it can be seen that the two
playback amplifiers are identical as ar e
the recording amplifiers. Circuits and
component values are usual for amplifiers of these types-no tricks are employed. Probably other circuit arrangements could be used, but the ones shown
operate efficiently and no revision is
contemplated.
Hum is reduced to minimal values by
heavy by-passing of cathode resistors in
low-level circuits in addition to d.c. on
the heaters. Measurements showed that
some residual hum voltages remain in the
output of the d.c. heater supply even
though heavy filtering is employed.
Recording equalization employs both
RC circuits and LC resonance. The resonant circuits are used in the cathode
returns of V 9ll and V IDll : a resonant frequency of 16,000 cps provides the opimum response at high frequencies. RC
equalizers in shunt with the plate circuits of VIA and Vu are used for playRI 18
6 . 3vA.C.
12v
D.C.
L -_ _
_
_
~
4
300v D. C.
r-+--<>
6
Fig. 4. The power supply is mounted on a separate chassis and connected to t he
amplifier. by means of a six-conductor cable. He a vi ly filtered direct current is used
for the heaters of tubes operating at low signal levels.
26
back. Resistors R9 and RlO are chosen
for maximum flatness of high-frequency
response when playing tapes recorded
with N ARTB characteristics. Some ad"
justment of values for R9 and RJO may
be necessary particularly if the head-gap
width differs appreciably from those
used in the Viking deck.
Resistors used in low level circuitsparticularly plate and cathode resistors
- should be selected with care if minimal noise levels are to be achieved. Except in the case of components used in
equalizing circuits the values of resistors
and capacitors are not critical. Plus or
minus 10 per cent tolerance was found
to be ample. Such components gave gain
'Vs . frequency curves for the two recording amplifiers which differed by no more
than 1 db; the same was true for the
playback amplifiers.
With the exception of the heater supp ly, the power-supply circuit is entirely
conventional. Details are shown in Fig.
4. A two-stage capacitor-input filter provides low ripple. The two voltage-regulator tubes shown in Fig. 3 are not required to reduce hum . However, then:
use does provide a constant plate-supply
voltage when the bias oscillator and r ecording amplifiers are till'ned off and on.
They also contribute to a low value of
effective power-supply impedance at low
frequencies where feedback (motorboating) can be a problem.
Two 6.3-volt heater transformers are
connected with their secondaries in series
to provide approximately twelve volts
d.c. at the heaters of tubes operating at
low single levels. A husky selenium rectifier is used in the conventional bridg'e
alTangement. The associated filter removes most of the a.c. ripple. Actually,
each 2400-!-tf capacitance consists of two
1200-!-tf units in parallel. Resistor R l l B
is adjusted to give the requisite heater
voltage.
Returning to Fig. 3 it is seen that
switch 8 I energizes the right recording
amplifier , electronic volume indicator,
and the bias oscillator. Switch 8 2 operates in similar fashion for the left recording channel. A glance at the electric
eyes immediately indicates whether. the
associated channel is operative and, more
important, it shows whether the bias oscillator is on or off. This is important
in preventing accidental erasure of
prized tapes.
Cathode followers are employed in all
output circuits. The hybrid, or monitor,
amplifier uses two cathode followers so
as to isolate the VU meter from the output. The relatively low impedance of the
meter introduces some waveform distortion. This distortion has little effect
on the meter indication but is most undesirable in the monitoring channel.
This same low impedance requires a
large electrolytic coupling capacitor. The
leakage inherent in electrolytic capaci-
AUDIO
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•
SEPTEMBER, 1958
tors is undesirable in the monitoring circuit but has no noticeable effect on the
meter indication . Separate cathode fo llowers solve these problems nicely.
Recording bias adjustment is provided
by variable resistors R 9.9 and R 100 which
are mounted neal' the bias oscillator in
easily accessible positions . Initial adjustment of bias currents is best accomplished by measuring the a .c. voltage
across a known resistan ce in series with
the r ecording heads. 'l'hen, t he VU meter
is inserted successively into jacks 15 and
16 and its indications noted. Thereafter,
the VU meter is used to check bias current as r equired .
Mechanical Details
Inspection of Figs. 1 and 5 shows that
the assembly consists of two sections,
each employing a separate chassis. The
bottom chassis contains the recording
amplifiers, bias oscillator, and associated
circuits; the upper chassis (which is inverted with the tubes projecting downward) contains the p layback amplifiers,
monitor amplifier, and volume indicators.
(Logically, the latter belong "downstairs" since they are associated with the
recording amplifiers but they were moved
up because they are more easily observed in this position.)
Practically all the circuitry associated
with the various amplifiers is mounted
on subchassis. These sub chassis are located inside the visible chassis and shockmounted thereto by means of self-locking bolts and soft rubber grommets. The
tubes project through the main chassis
throug'h holes cut sufficiently large to
clear the tube shields with plenty of
room for movement. This system for
shock mounting is recommended- absolutely no trace of microphonism has been
observed even under conditions of severe
mechanical vibration. It is important,
however, to proportion the moving mass
to the stiffness of the mounting so that
the natural frequency of oscillation is
very low. Otherwise, the benefits of
shock mounting are questionable. All
heater wiring is run between the subchassis and the main chassis. The wires
pass through small grommeted holes im mediately adjacent to the heater terminals of the sockets. This arrangement
effectively shields the heater wiring and
reduces the shielding required on signalcarrying leads. This procedure improves
high-frequency response.
The outer chassis assembly is stiffened
by two hand-made brackets shown in
Fig. 5. 'rhese are made of heavy aluminum stock. Weight is reduced by using
aluminum for chassis and panels.
The tape deck can be fastened to the
amplifier unit in a number of ways.
After several arrangements were tried
the one shown in Fig. 6 was found most
suitable. Two aluminum "Tee" bars were
drilled and tapped to standard rack di-
AUD IO
•
Fig . 5 . Rear vie w o f u nit sh ow ing in verted chassi s hou s ing pl ayba ck amp lifie rs.
mensions. Then a couple of "adaptors"
were fabricated of aluminum to hold the
deck at an angle. This permits maximum
ease in tape handling and retainers are
not necessary to hold the reels in place
as would be required if the deck were
mounted vertically . Some form of shock
mounting for the tape deck is desirable
to minimize mechanical noise.
The over-all package lacks the easy
portability of some commercial recorders. Even though all aluminum construction is employed the amplifier, tape deck,
and power supply weighs approximately
fifty pounds. However, the unit fits
nicely into the trunk of an automobile
and no transportation difficulties have
been encountered in the fi eld .
Operation
The Viking FF75SR tape deck, like
several other commercially available
units, is fitted with a single-track erase
head, a single-track recording and playback head, and a pail' of heads mounted
in-line for stereo recording and playback. In the case of single channel recording the erase and single track heads
are connected in the usual fashion by
means of suitable patch cords and the
appropriate stereo head is used for
playback. This arrangement is fine provided that material is r ecorded on only
one side of the tape. Otherwise, adjacent
track cross-talk is a problem. Where this
(Continued on page 53 )
Fig . 6 . The tap e deck is attached to t he amplifier by means of tw o " Te e " ba rs. A lt hough t he powe r supply is shown next to t he amplifie r it should b e no cl o ser t ha n
. thre e feet whe n it is b e in g u sed .
27·
SEPTEMBER, 1958
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Sound Reproducing SystemsMonaural, Binaural, Monophonic, and Stereophonic
HARRY F. OLSON ':'
A clarification of the definitions of the various types of systems encountered currently,
as presented by a recognized authority in both acoustics and sound reproduction.
HE REPiWDUCTION OF SOUND is the
process of picking up sOlmd at one
p oint an d i:eproducing it either at
the same p oint or some other p oint either
at the same time or some subsequent
time. There ar e many different typ es of
systems emp loyed for the r eproduction
of sound. In this connection, sound r eproducing' systems in use today may be
classified as fo llows: monaural, binaural,
monophonic, and ster eophonic. Ther e app ears to be considerable conf usion in the
proper use of these ter ms in design ating
the four f undamental typ es of sound reproducing systems. The r esult is an almost indiscriminate application of the
terms to unrelated systems. For this
reason it appear s desirable to defin e and
describe the use of the fo ul' terms.
Therefore, it is the purpose of this paper
to defin e and describe the char acteristics
of monaural, binaural, monophonic, and
stereophonic sound systems.
T
STUDIO
ORIGIN AL SOUND SOURCES
88888
* RCA Labomt01'ies, P 1'inceton, N . J .
Binaural
A binaural sound r eproducing system
is a closed cir cuit typ e of sound r ep roducing system in which two microphones,
used to pick up the original sound, are
each connected to two independent corresponding tra nsducing channels which
in turn ar e coupled to two independent
corresp onding telephone r eceivers worn
by the listener , as in Fig . 2.
Monophonic
A monoph onic sound rep roducing system is a field typ e sound r eproducing
system in which one' or more micr ophones, used to pick up the origina l
sound, are <ooupled to a single transducing channel which in turn is coupled to
one or mor e loudspeaker s in r eproduction, as in F ig. 3.
Fig . 1. Monaural.
Monaural
A mona ural sound r ep roducing system
tr ansducing chan nel which in turn is
coupled to one 0 1' two telephone r eceivers worn by the listener , as in F ig. 1.
is a closed circuit type of sound r eproducing system in which one or more micr ophones ar e connected to a single
Stereophonic
A ster eophonic sound r eproducing sys(Con tinued on p age 56)
STUDIO
STUDIO
ORIGINAL SOUND SOURCES
(9
STUDIO
ORIGINAL SOUND SOURCES
e
NAe D ( § ESe
MICRO PHONE L
DUMMY
,----,
,
I
-,-,
I
,....-_.1_-I
•
I
:
I
I
---T--I
.- ~
I
-
.... ...
I
L., _ ~....!
l __ ::'
88GGG
SUBJECTI VE
LOCATION O F REPRO
DUCED SOUND'
SO URCES
TELEPHONE
RECEIVER L
TELEPHONE
RECEIVER R
Fig. 2. Binaural.
SRX
= SRI'
SR2--- SR5
REPRODUCED SOUN
SOURCE S
GGSGG
SlAIJECTIVE LOCATION OF REPRODUCED
SOUND SOURCES
~
LISTEN ER
ROOM
o
Fig . 3. Monophonic.
Fig . 4. Stereophonic.
28
LI STENER
ROOM
AUDIO
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•
SEPTEMBER, 1958
NEW .JENSEN CN-100 3-WAY SYSTEM
A new 12" 3-way system, the CN-IOO reproducer gives a new small-scaled
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~et
.
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'. ;
.:. ;
Heart of the Tri-ette is the new Flexair 12" woofer with its superlow free-air resonance of 20 cycles and
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Fiberglass lining. Special 8-inch midchannel handles the range from 600 .to 4,000 cycles, through L-C
crossover network. RP-I03 Tweeter carries the response from 4,000 to 15,000 cycles. 13 'Va" H ., 25" W.,
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ST-945 Base . For table or shelf. Net Price •••.. • 6.46
KT-33 :i-WAY SYSTEM KIT
KT-34 TRI-PLEX II SPEAKER KIT
Includes basic speaker components for 3-way system identical
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Includes Flexair 12-inch woofer, special 8 inch m-f unit, and
RP-I03 compression h-f unit. Complete with control, crossover
network, wiring cable, and full instructions for building enclosure
and installing speaker system. Net Price $80.00
Components used in the TP-250 Tri-Plex II reproducer.
I5-inch Flexair woofer, new compression driver m-f unit,
and new phase correcting supertweeter. Response frQm' 16 cycles
to upper limits of audibility in Jensen Bass-Superflex
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building enclosure. Impedance 16 ohms. Net P;ice $179.50
NEW TP-250 TRI-PLEX II 3-WAY SYSTEM
This latest version of the Jensen Tri-Plex reproducer incorporates the extreme bass capability of the 15" Flexair ",,:oofer, in combination with advances in midch annel and supertweeter deSIgn . ThIS beautIful umt outperforms any speaker system of comparable size or
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Response range, 16 cycles to beyond audibility. Components available also in kit form (see
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·Trademark
AUDIO
•
-1I.e nteny
W
Division of The Muter Company
MANUFACTURING COMPANY
6601 S. laramie Ave., Chicago 38, Illinois
In Ca~ada: J .. R. Longstaffe Co., Ltd., Toronto
In MeXICO: RadIOS Y Television, S.A., Mexico D.F.
SEPTEMBER, 1958
29
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Hybrid Feedbacks for
Power Amplifiers
HERB ERT I. KE ROES':'
While feedback in most amplifiers is partia lly de pendent on the load impedance , it is possible
to eliminate this effect to a large extent with a cla imed improvement in over-all performance.
has been evinced in
the system of Hybrid Feedback '
as developed and used in the
Acrosound Ultra-Linear II power amplifier. This system prevents interaction
between feedback circuit and load;
consequently its use results in a feedback system inherently more stable than
the conventional systems now used.
The circuit has been developed from
a consideration of the unique properties
of the hybrid coil, a device long used
in telephone com munication to permit
amplification in both di.J:ections on a
telephone line without interaction. This
property of circuit isolation is put to
use in a similar manner between feedback and output cil'Cuits of an amplifieI'.
In its usual f01' m, the hybrid coil is
a three-winding transformer composed
of a primary winding and two seriesconnected secondar y coils of equal
turns, and is shown diagrammatically
at (A) in Fig. 1. If power is fed to
the primary, it is divided equally between each load r esistor, the two load
resistors being of equal value. Another
resistor is used to supply balance, and
is shown connected between the junction
of the two secondary windings. When
all circuit resistors a re chosen in a certain r elationship, the circuit has several
unique properties. A voltage placed in
series with one load will not be reflected
into the other load. A voltage p laced
in series with the balancing resistor will
not appeal' in the primary winding of
the transformer. The hybrid arrangement can then evidently be used to divide output voltage between load and
fee dback circuit without interaction. It
would not be economical to divide power
equaUy between load and feedback circuit, hence the section of the secondary
which energizes the feedback circuit is
composed of just enough turns to supply the requisite a moun t of feedback
voltage.
The solution of a hybrid circuit where
the secondary winding is comprised of
M
UCH INTEREs'r
* Am'o pj'oducts Co. , Philadelphia, Pa .
1 Pntent pendin g.
(A)
~
'~" ~W;'"
Fig. 1. Sche matic of vol tag e and curre nt
re la ti o ns hip s of t he hy bri d fee dba ck
arrangem e nt .
two series-connected coils of equal turns
is well known, and to be found in most
standard texts. Where t he secondaries
are not of equal value, the solution is
not easily available, and will be developed here. Ano ther property of the
hybrid circuit will also be developedone which, to the best of the author's
knowledge, has not been previously disclosed.
As used in the Ultra-Lineal' II amplifier, the output transformer forms a
hybrid coil, and the output circuit is
shown at (B) in Fig . 1. The circuit of
the output transformer alone is shown
at (C). The voltages and impedances
appearing across the various windings
are as follows:
E" The open·circuit plate-to-plate voltage of the output stage.
Eb A voltage introduced into the load
circuit to determine its effect on t he
feedback voltage.. It may be an
equivalent voltage generated by a
change in load impedance (an as·
sumption valid by t he compensation theor em), or a back emf gene1'at ed by the load.
e The voltage acro ss the primary winding of the transformer, composed
of n turns:
e} The voltage across the winding section composed of n} turns and
which connects to the feedback circuit.
e, The voltage across t he winding section composed of n, t urn s and Wllich
connects to the loa d.,
ZI The f eedback load impedance.
Z , The output load impedance.
Z, The balancing r esistor.
Z , The plate impedance of t he output
tubes.
We may write the equations for the
voltage drops in each loop in terms of
the loop currents a nd impedances by
Kirchoff's law, and these give relationships (a), (b), and (c) below. Equations (d) and (e) ar e r elationships that
exist in any transformer, the sum of
the amp ere tUl'll!, in each winding being
zero, and the exact proportionality between the open circuit voltage a nd turns
in each winding.
(a) e =E" - Z4i
(b) e1= Z a'iz - (Z 1 + Z S ) i 1
( c) ez = Z siz - (Zz + Z s)i 1 + Eb
(d) n 1i 1 + n zi z + nsis = 0
(e)
e
81
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z
The r elationships of (a) and (e) may
be substituted into (b), (c), and (d) ,
to give the following three equations in
which all currents are expressed in
AUDIO
30
6
n
•
SEPTEMBER, 1958
NOW. • •
THE MARK
OF
CONTINUED LEADERSHIP
New, Dual FM-AM Stereo Tuner and Preamplifier
by
The Model 690 is clearly the most original,
the most versatile, and most brilliantly engineered stereophonic component to make its
appearance to date.
Embodied in one chassis are two high quality
tuners: FM and AM, with a complete stereo
preamplifier. The FM and AM tuners operate
independently of each other. Ideal for FM-AM stereo, this unique
feature also permits two different broadcast programs to be played
simultaneously in different parts of your home. It also enables you
to record one program (AM for example) while listening to a
simultaneous FM b roadcast. The Model 690 also has an FM multiplex output jack for FM-FM stereo.
Two precision tuning meters are provided for accurate station selection, one for FM reception, and the other for AM.
Also featured in the AM section is a broadnarrow band-width selector.
The preamplifier section of the 690 consists of
two identical preamp units. Volume, tone and
stereo balance controls are included. The outputs may be fed to any basic stereo amplifier
such as the Pilot SA-232 or SA-260.
The Model 690 provides inputs with equalization for stereo records,
stereo tape heads, tape recorders and dual microphones . There is also
an output for making stereo and monaural tape recordings. Housed
in a modern, low silhouette metal cabinet with brass control panel,
the 690 is priced at $269.50, complete.
Slightly higher in West.
Complete specifications at your high fidelity dealer or write to:
Pilot Radio Corp. 37-04 36th Street, Long Island City 1, N. Y.
Electronics manufacturer for more tban
AUDIO
•
39
SEPTEMBER, 1958
years.
31
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th e loa d circuit will n ot produce a curr ent flow in the fee dback circuit.
An impedance variation in the output
circuit or a back emf generated by the
load imp edance will ther efor e not be
transmitted into the fee dback circuit.
W e sha ll now show that Z i may have
any value f r om zer o to infinity, and
will not affect the proportionality of
voltage induced by Ea in the fee dback
cireuit, or change the phase of the induced voltage. To prove this We will
r.
n , n 2 Z.
take the r ela tionshi p Z S=--o
and
n-
transpose Z 8 a nd Z . . This becomes
r.
Z ,;n2
Z . = - - This is t hen inserted into
n1 Z
H
-I
the expression for i l ' A lso let E b = O.
-E
n ,Z 2+ Z S(n , +n 2)
I"
The Acrosound Ultra -lin e ar" amplifier d iscuss e d in this article .
terms of the applied voltages Ea and
E b • W e may then solve these f or the
current in the f eedback circuit, 'ilJ and
the load current, i z•
-n
n
,
E a = - (Z
Z ~ ) '1.,1 + Z ,,;'1',2
':-'1+
.
n 2 Efa - E b =Z 3~' 1
-
n
n , Z I~.
n'
(Z 2 + Z :; )''t 2 + -nz Z 41,'
n
0 = n ,i , + n Z i 2 + n 3iS
The easiest method of solving these
equations is to effect a solution by means
of determinants. W e obtain the f ollowing 'solutions for i 1 and i 2 •
u
Z,Z2+ .G 2Z. ( 1 + '!!..!.)+ Z1 Z s
nQ
11.
,)
(n ,+ n 2)2
+ Z l ..:.....:....--=-:(1+~
II
n ,n z
The denomina tor lll ay then be f actored,
and we find that one factor cancels with
a similar expr ession in the numer ator,
glVll1g the f ollowing solution for i,.
1
+-
-
-
where
If we now specify the condition that
E a is zer o a nd E b is not equal to zero,
we find that i, is zero when Z s is equal
in value to 1! , n z Z . / n2 . If then Z s is put
at this va lue, a voltage inj ected into
Fig . 2. Compl e te schematic of the Ultra -Linear II amplifier.
32
i , .- Ea Z -.G -Z---.!.. + ':...l .J +-.!....
1!,
i!,
n2
Note tha t the only imp edance terms in
this expression are those of the r esistor
in the f eedback circuit and the value
of the balancing r esistor. If these are
set a t a fixed value, the current that
flows in the fee dback circuit is constant,
ther ef or e the voltage developed across
the fee dback load is constant and independent of the value of the loa d Imp edance Z 2'
The hybrid system is normally oper ated so th at the nominal value of Z 2
produces a loa d current equal in value
to i , . No CUlTent then flows in the balan cing r esistor Z s and it consumes no
power . To find this r elationship, E b is
put equal to zer o and the expr essions
f or 'i , and i2 are equated. This gives
the r elationship Z ,jZ 2 = 11,/ 112, The
turns r a tio between t he f eedback and
load sections of the secondary winding
is adjusted to this value.
Finally, we note that if no current
flows in the balancing resistor, the
complete secondary of n , plus n 2 turns
f eeds a secondar y imp edan ce of Z , plus
Z . ohms. The turns r a tio between secondar y and p rimar y is then nd (11, +
n 2 ) z = ZI, / ( Z, + Z 2)' ZI, is made equal to
the correct plate-to-plate impedance of
the output tubes and the turns ratio
computed.
In the Ultra-Linear II amplifier, Z s
is made variable. This provides. a variable damping control which changes the
ratio between voltage and current feedback. With the control adjusted to
(Con tinued on page 51)
AUDIO
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•
SEPTEMBER, 1958
Ne~
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G-E " Golde~ Class1c "
stereo-~ag~etic
cartridge
nF!
HiV
" GOLDEN CLASSIC" Model
G~ . 7 (s.ho w n) wilh .7 $23 95 '
mil diamond sty lu s
"GOLDEN CLASSIC" Model
GC · 5 (for professional·lype
lone arms) wi lh .5 $26 95 '
mil diamo nd styl us.
"STEREO CLASSIC " Model
CL·7 wilh .Tmil syn- $1 6 95 '
thetic sapphire sty lus
*Monufocture r' s su gg es ted resal e
pri ces,
makes stereo a practical reality- at a realistic price!
• Fully compatible with both stereophonic and
monaural records
• Frequency response 20 through 20,000 cycles
• " Floating armature" design for increased compliance and reduced record wear. Effective mass
of stylus approximately 2 milligrams
TEST REboRDS: 0 10 15KC WbrRJ STEREO IA_
15KC 10 20KC RCA MONAURAL 12-5-69
+15
..
+10
+5
DB. 0
~
.
-
-5
-10
- IS
"'-
.
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I"
"100
1~12'!i!'IIH~1
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f
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IOKC 20KC
CIS
Smooth response on both stereo and monaural records.
Consistently hi g h sepa ration between stereo ch':lnnels.
• High compliance in all directionsLateral compliance 4, x lO-G em/ dyne
Vertical compliance 2.5 x lO- G em/ dyne
• Recommended tracking force with professionaltype tone arm 2 to 4 grams
• Consistently high separation between channel
s_ignals
(Specifications for Model GC-5 with .5 mil diamond stylus)
Stereo is here! General Electric makes it official
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Electric Company, Specialty Electronic Components Dept., Section 598, W. Genesee St.,
Auburn, N. Y.
GENERAL. ELECTRIC
AUDIO
•
SEPTEMBER, 1958
33
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Hearing, the Determining Factor
for High-Fidelity Transmission *
HARVEY FLETCHER
In three parts-Part 3
FROM THE ARCHIVES OF BELL TELEPHONE LABORATORIES
This is perhaps the first authoritative study of the requirements for ideal systems for the
transmission of speech and music. Much of our present-day knowledge and practice
stems from this article , which presents conclu sions derived from measurements of
hearing on more than 500,000 people during the World's Fairs in 1939 and 1940.
If loudness were the criterion of
judged quality of reproduced speeeh, the
effect of limiting the band has been measured. The loss in loudness due to frequency-band limitation depends upon
the' level at which the speech is reproduced . In Table VI the values are given
for two loudness level '. The upper half
of the table gives values for an initial
loudness of 215,000 loudness units corresponding to a loudness level of 110
decibels and the lower half of the table
gives values for an initial loudness of
4000 loudness units corresponding to a
loudness level of 59 decibels. When it
is realized that under the most favorable circumstances the cal' can detect
loudness differences only when they are
greater than 3 or 4 per cent then it is
seen that the elimination of frequencies
above 5000 or below 100 would not be
detected as any loudness difference. It
would be useful if we had a relation such
as that exhibited in Tables IV and V obtained from judgment tests of the artistic. qualities of the speaking voice. From
all these data then it is seen that the frequency range can be considerably more
restricted for transmitting speech than
for transmitting music, before senOllS
impairment results.
TABLE IV
MU S I C-JUDGED Ql' A [.I'l' Y
Judged
Qu ality
High - Pass
Filter Cutoff
Low-Pass
Filte r Cutoff
100
97
93
90
85
80
70
60
50
40
30
20
10
40
70
80
90
100
120
140
180
220
270
325
500
850
15 ,000
12,000
9,000
7,800
6,500
5,600
4 ,800
4,000
3,600
3,000
2,500
1.700
850
"PABLE V
SPEECH-ARTICULATION
Articulation
High-Pass
Filter Cutoff
Low-Pass
Filter Cutoff
per cent
98
98
98
96
94
90
80
70
60
50
40
100
250
570
720
960
1,500
1,920
2,300
2,600
15,000
12,000
7,000
5,000
3,900
3, 100
2,300
1,970
1,700
1,500
It was seen that the range from the
peak value of the loudest phonetic sound
to the faintest was 56 decibels but for
usual conversation this is reduced to
about 40 decibels. One would not expect any degradation in transmitted
speech until the intensity level range is
decreased below 40 decibels. Measurements on the articulation of conversational speech for smaller ranges have
been made.l 1 These were given in terms
of the level of the speech above threshold
and masking of the noise. The noise used
produced a uniform masking between
250 and 10,000 cps, dropping off at
either side of these limits. First let us
consider conversational speech of men
and assume the listener wishes to hear
it at levels he would obtain if he were
2lj2 feet from the speaker instead of 20
feet. The values in Table I would then
be raised 18 decibels. From these values
then we must deduce the level of the
speech above the standard threshold if
we are to apply the data referred to
above.
Experiments in our laboratories have
shown that the threshold level, for observers with acute hearing of conversational speech which is un distorted, is at
a long root-mean-square level of 5 deciJ1
Loc cit., p. 298.
bels. Now the long root-mean-square
level for speech was found by Dunn and
White to be 10 decibels below the maximum root-mean-square level in %-second
intervals. Consequently at 2lj2 feet from
the speaker the men's conversational
speech will be 63 decibels above threshold. The articulation values given in
Table VII are taken from Fig. 148 of
"Speech and Hearing."9 The noise levels
corresponding to the various values of
masking were obtained directly from the
curve in Fig. 3 of the paper, "Relation
between Loudness and Masking."4 In
computing the range the highest level
was considered to be the maximum 'rootmean-square value in % second, namely,
78 decibels. If we used long root-meansquare values of both speech and noisp
these ranges would all be reduced 10
decibels. These range values will of
course depend upon the spectrum of the
noise but the values given here an'
enough to show that when the range of
a system for single-frequency tones is 40
decibels from 100 to 7000 cps very littlp
9 Harvey Fletcher, "Speech and Hearing,"
D . Van Nostrand Company, New York,
N. Y., 1929, p. 75.
TABLE VI
SPEECH--LoUDNESS
Loudness
per cent
2 15,000 =: 100
98
90
80
70
60
50
4,000 =: 100
98
90
80
70
60
50
AUDIO
34
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High-Pass
Low-Pass
Filter Cutoff Filte r Cutoff
40
100
200
300
450
600
800
40
200
500
770
950
1, 125
1,250
•
15,000
5,000
3,500
2,100
1,500
1,100
800
15 ,000
4,000
2,500
2,000
1,700
1,450
1,250
SEPTEMBER, 1958
............•.
........•.••.
THE \\400"
STEREOPHONIC
MASTER
AUDIO
CONTROL
• Eight pairs of stereo inputs, 4 pairs for low·
level, 4 pairs for high·level.
• Seven pairs of permanent connections,
4 low·level, 3 high·level.
• High·gain microphone preamplifier.
• Push·button function and channel selection.
• Built·in crossover network, with complete use
of the tone controls at all times.
• 3·position, lever·type Rumble Filter.
• 3·position, lever·type loudness Contour Control.
• Special input for ceramic stereo cartridge.
• Channel indicator lamps.
• Power·on indicator lamp.
• Four auxiliary AC receptacles.
• Three cabinet finishes, for any room decor.
AUDIO
•
SEPTEMBER, 1958
35
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TABLE VII
CONVERSATION SPEECH-SPEAKER
FROM LISTENER
2%
FEET
=
Level of speech above threshold
63 db
Long root-mean-square intensity
level
= 68 db
Peak level in 1h-secoud intervals
exceeded 5 per cent of the time = 85 db
Root-meau-square level in % -second
intervals exceedel only 1 per cent
of the time
= 78 db
Articulation Masking
Noise Level
Range
per cent
97
95
88
77
55
28
0
10
20
30
40
50
10
36
46
57
67
77
68
42
32
21
11
-1
01' no distortion is produced when speech
is transmitted. However, if we wish the
noise from the system to be inaudible,
the levels must be below the curve of
Fig. 3. This means a range of 48 decibels, that is, from 78 to 30 decibels in the
frequency region where the maximum
speech levels occur.
the man walked to the center and made
a phone call. After another conversation
between the man at center and the woman at right, the man walked to the left
jingling keys and opened a steel cabinet
at left, and so on.
For the single-channel condition the
plot was the same but the props were
~ hifted in position and the action was
adjusted to the restricted space. For
each judgment the observers listened
first to the single-channel full-frequencyrange version, and then with the smallest
possible interval to the filtered twochannel version.
In the two-channel system filters were
introduced and a ' nuinber ' of observers
indicated which system they prefened.
In Table VIII are 'shown the results.
When the cutoff for the low-pass filter
was somewhere between 5500 and 7000
then one half the group preferred the
two-channel system with filters and the
ot.her half preferred the single-challnel
TABLE VIII
ONE-CHANNEL VERSUS TWO- CHL\ NNEL
TRANSM ISSION
Multiple Channel Transmission
The third way in which the quality of
the transmission can be improved if
there ar e no economic deterrents is by
using more than one channel for the
transmission. We have found that the
quality of reproduced music is very
much improved by using two or three
channels. As stated above, such transmission makes it possible to produce apparent motion of the sound and provides much greater possibilities in dramatic productions.
Some preliminary tests to determine
in a quantitative way the increased
quality due to using just two channels
instead of one have been made in OUI'
laboratories. In one of these a dramatic
skit used very simple program material and was designed to tie together
smoothly a number of sounds rich in
high frequencies. It opened with a man's
voice dictating a letter to a woman on
right. Then the man walked from right
to left and back and engaged in a short
conversation. The typewriter started and
Low-Pass
Cutoff
Speech and Noise
Per Cent Preference
One Channel
Full Range
Two Channels
Limited Range
3
10
39
71
85
97
90
73
61
29
15
3
19
47
97
81
53
15,000
11 ,000
8,000
7,000
5,500
3,800
27
Hi gh - Pass
Cutoff
125
250
500
which transmitted all frequencies from
40 to 15,000 cps. Also it is seen that
according to these tests the two-channel
system filtering all frequencies below
500 was considered as good as the wideband single channel. Similar tests were
nlade in a very preliminary way on a
45-piece orchestra during a boadcast and
the single channel was found to be
equivalent to a two-channel with a lowpass cutoff of about 5000 cycles. These
1\
! \
\
so
1\
Fig. 3. Hearing
limits far
pure
tones- typical listener in ty pical
residential
room
noise .
r'-.
~//.
~
~ ra;~
''''~
~~ ~ 1%
1/
~ ~ ~~1I
n
20
..
J
1000
FREQUENCY IN
•••
'0000
TABLE IX
Preference
Low-Pass
Cutoff
8,500
5,500
4,510
3,750
2,850
Binaural
Diotic
per cent
per cent
68
58
70
50
42
32
42
30
50
58
tests are very preliminary and are only
indicative of what more accurate tests
might show. No direct judgment tests of
a quantitative nature have been made
hetween a two- and a three-channel system but comparison between them indi<lates that three channels are definitely
better. This is particularly true when the
sound is r eproduced from a stage into a
large hall.
Although head receivers are seldom
used as receivers to listen to music, it
may be interesting to describe some tests
made in our laboratories to test the
.i udged quality of music transmitted by a
binaural system versus that transmitted
by a diotic systelll. In these tests the
listener had a pail' of high-quality headphones clamped on his ears. He could
listen under condition .A (binaural)
where two high-quality circuits and microphones were used to transmit music
to him; condition B (diotic) where one
cha.nnel and one microphone were used
to transmit to his pair of headphones.
III the diotic system the full-range of
frequencies frol11 40 to 15,000 cps was
transmitted. In the binaural system lowpa.ss filters were introduced to eliminate
a part of the upper range. Twenty-five
engineers took part in the preference
tests. The Philadelphia Orchestra, playing various selections, was used as the
music for the test. The results are shown
in Table IX. The percentage of persons
preferring the binaural system with limited range is shown under the title
BINAURAL. These results show that a
binaural system which transmits a frequency band greater than 3750 cps was
preferred to a diotic band transmitting
the entire range. In other words, if a
band 8000 cps wide or greater is available for a transmission channel, this
indicates that better results may be
achieved by using two channels binaurally than one diotically. It is rather
remarkable that one half of the observers prefened a binaural system having
a.ll frequencies above 3750 cps eliminated rather than a single-channel diotic
system transmitting all frequencies between 40 and 15,000 cps.
Before definite conclusions can be
drawn as to the improvement of one
versus two ve rsus three channels for
various purposes, llIuch more data must
be collected. It may not be economically
feasible to use 1110re than one channel in
CYCLES PER SECON D
(Con.tinued on pag e 53)
AUDIO
36
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•
SEPTEMBER, 1958
i
MONOPHON Ie
ORP
STEREOPHONIC )
EON
The finest amplifiers are " linear" in the lab, but not in the living \f..1~~~~--;I:n-;:c. provides two versions of the great new ORPHEON - one
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sive new feature accomplishes this amazing feat. And AAS * is
found only in the great, new ORPHEON amplifier. Using an
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• 80 watts stereo output (peak 160 watts )
• Inputs for radio, TV, htape , miCrO~h~yn:t::dsegment
• Output meter reads power 0hutputt in ~:tgt;,e~t
magnetic or crystal p ono on eac
tape output in volts on eac sys. em
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It is also a sound-level Meter Wlt~ AAS
• Tape and monitor outputs on ~ach system segm~nt
• Calibrated Microphonic ACou~tlcalhprobe
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be used as public address mlcrop one or 0
each system segment
• 24 positions of equalization for each system segment
• Cathode-follower tape output on each system segment
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• DC on input filaments
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• At least 18 db of bass and treble boost attenuation plus
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~
• FM-88 to 108 MC • AM-SOO to 1600
Model TUMK, Kit ............ :.: ..... $49.95
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AUDIO
•
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without AAS* and Acoustical Probe, factory-wired, complete
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Model STAM40A-20-watt stereo system (80 watt peak, monophonic), with AAS * -factory-wired complete ............... $289.50
A superb 40-waU amplifier
which suppor's a sy mphony
orch es 'ra with live, crisp,
brilliant distortion-free reproduction,
KC • Output tuning meter. cathoaefollower output • Convenience outlet
• Phono, FM, AM, TV switch and Inputs
• Foster-Seeley discriminator • Flywheel tuning • 2 limiters • Ferri-loop
• 3-gang variable condenser • Logging scale. 13" x 4'14" x 9314" . Cage
at additional cost .
Model TUMW, Foctory-wired ...... $59.95
e
• 24 positions of equalization. DC on
input tube filaments. Volume or loudness control. S mv full output. Rumble filter • Muting switch • Convenience outlet. Output meter reads power
output in watts, tape output in volts
• Separate and independent tape output level potentiometer • CathodeModel AMK, Kit ........... ... ..... .. . $69.95
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follower tape output • Internal grid
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OCEANSIDE, N. Y.
37
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,
The Stereo Phasing Problem
C. C. McPROUD
The techniques of stereo recording have not yet shaken down sufficiently that
we are completely sure of the phasing of the two groove walls. This may help explain some of the inconsistencies which many readers have mentioned in letters.
AUDIO ETC for this month, Mr.
Canby brings up a question which
has engaged the attention of many
others during the past few months"When I am set up to play records with
a stereo pickup, I find that if the system is properly phased for monophonic
records, it is out of phase when I play
a stereo record; why is thi s~"
The writer first encountered this condition last February at the Los Angeles
High Fidelity Show. In the Pickering
exhibit room, a system was set up with
the speakers phased correctly for monophonic records, with the sound apparently coming from a virtual speaker
directly in the center. Shortly afterward, during the playing of the Capitol
Stereo Demonstration Record, Ed Uecke,
Capitol's chief engin{}~', came in and
the first thing he said was, "That's out
of phase."
Since Mr. Canby had discussed this
problem with us recently, we set out
to find out why this should be-for we
had ah-eady noticed it ourselves on several occasions. To begin with, let us
consider the stereo pickup. For the purposes of this discussion, we are using a
magnetic cartridge, although the same
conditions obtain with ceramic or crystal
types.
Figure 1 shows the hookup of a
typical magnetic cartridge with four
terminals. For a movement of the stylus
as shown by arrow A, the moving elements are carried as shown by the arrows Band C. The convention used
here is that a movement of the element
in the direction of the arrow generates
a signal of positive polarity at the end
of the coil by the head of the arrow.
Thus for a lateral movement of the stylus, positive signals are generated at
I
N
.+
Vto
Fig . 2. Reversing polarity of one COil
provides reproduction of vertical records.
~A
Fig . 1. Connections of stereo pickup coils
for reproduction of lateral records .
terminals 1 and 3, and negative signals
at terminals 2 and 4. For lateral records only, therefore, terminals 1 and 3
can be connected together, and terminals
2 and 4 can be connected together. If
the two coils are paralleled in this
manner, any vertica l components in the
record will be cancelled out, which will
reduce any rumble that may be present.
Figul'e 2 shows the same pickup
actuated by a vertical movement of the
stylus, arrow D, producing positive signals on terminals 1 and 4 as generated
by the movements of the elements indicated by arrows E and F. With this
hookup, lateral movement of the stylus
generates two signals which are cancelled out, and onl y the vertical signal
will appear at the output.
Fig~£1'e
3 shows a three-termin al
pickup, such as Stereotwin and ESL,
which have the coils conn ected so that
the two "hot" leads are in phase on
lateral signals. This is, of course, the
same condition that would exist if terminals 2 and 4 of the fo ur-terminal
pickup were connected together as a
common terminal, as is generally the
case. When lateral records are played
with a pickup so connected, the output
should be about equal to that from either
coil alone; if the coils are improperly
phased, there will be very little output
when the two are paralleled .
In the original presentation of the
Westrex cutter, the arrangement was
like the coils in Fig. 1 without the coils
being connected in parallel as they are
shown in the figure . Using the same
convention for polarity, it will be noted
that to cut a lateral record the two
signals had to be out of phase with
respect to the tops and bottoms of the
two coils. It seems to be the COncensus
of r ecording engineers that the stereo
groove should be cut so that the predominant modulation of the groove is in
the lateral direction, which means that
the signals were fed to the coils out of
phase. This has since been corrected by
an RIAA standard which defines the
polarity such that when two identical
signals are fed to the cutter in phase,
the groove will have lateral modulation
only. It is quite possible, however, that
before this standardization many records were cut with the polarities reversed, which r esults in the difference
in phasing between monophonic and
stereo records.
How to Tell Phase
It is difficult to explain how to detect
the propel' phase. With monophonic
records, a system should be set up so
that the sound appear s to come f rom a
point half way between the two speakers. This is easi ly detectable by anyone.
But on stereo, the two speaker s are
r eproducing different signals, even
though some components of the signals
are the same. Mr. Canby describes the
out-of-phase sound as like hearing it
through vertical venetian blinds, giving
a sound like a ripple as you walk back
and forth in front of the speakers. John
Bubbers of B&C Recording Company
says the room seems to have standing
waves in it, which is an engineer's way
of saying just what Mr. Canby says.
Our suggestion is that you walk back
and forth in front of the two speakers
- if the sound is smooth, with only a
gr adual changing effect from one
speaker to the other, the system is in
phase; if the sound seems to jump back
(Continued on page 79)
c
Fig . 3 . Three-terminal pickup should be
polarized so that shorting "hot" leads
will reproduce lateral discs.
AUDIO
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•
SEPTEMBER, 1958
DEBUT
of the Bozak Urban enclosures for
the B302A and B305 speaker systems.
See and hear them at the Audio Fairs
and franchised Bozak dealers-or write
The R. T. Bozak Sales Co. Darien, Conn.
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Audio Engineering Society
TENTH AN N UAL CONVENTION
September 29-0ctober 3 , 1958
HOTEL NEW YORKER
34th Street at Eighth Avenue , New York City
Program 01 Convention Papers
R
ETURNING to
the theme of the first
audio show ever held in the U. S.,
-Professional Audio Equipment- t h e
Audio Engineering Society is t his year
holding its own show, concurrently with
the New York High Fidelity Show, with
all of the exhibits devoted to non-consumer
equipment. The growth of the high-fidelity
industry has so greatly overshadowed in
magnitude the market for professional
audio equipment that t h e shows-which
were originally designed for the engineer
-now have little attraction for the manufactUl'ers of test and measurement gear.
This year they have their own show, and
engineers will welcome the change.
The convention of t h e Society brings a
wider range of papers than ever before,
and the compl ete progr am follows:
Monday, September 29.
9:30 a.m. THE TRANSISTOR IN AUDIO
CIRCUIT APPLICATIONS
F. M. Dukat, Raytheon Ma nufac turing
Company, Chairman.
Direct Coupled Transistor-Tube Audio
Amplifier for R a dio and TV.
Wi lliam F. Pal mer and G. Schiess, Sylvania Electric Products, Inc .
Applying' the Tra nsistor in a Stereophonic
Tape System.
Dwight V. Jones, Genera l Electric Co.
A 25-Watt High-QuaJity Transistorized
Audio Frequency Power Amplifie'r
R. Minton, RCA.
Design of a Stereo Control Center
Paul A. Grace, Raytheon Mfg. Co.
1 :30 p.m. STEREO PERCEPTION
H. E. Roys, RCA Victor, Chairman.
Physiologica l and Psychological Aspects
of Ste'r eo
Dr. Fred P . Beguin, G.E. Co.
Psychological Factors Govel"lling the Binaural Effect
John A. Cooley, Georgetown University.
Stereo as an Integral System
Norman H. Crowhurst, Audio Design
Services.
Determining the Arena of Stereo Perception
A. B. Cohen, Advanced Acoustics Co.
7:30 p .m. MUSIC AND ELECTRONICS
Prof. Vladimir Ussachevsky, Dept. of
Music, Columbia University, Chairman.
Severa l Proble,m s in Musical Acoustics
Prof. Melville Clark, Jr., Massachusetts
Institute of T echnology.
Specialized Equipment used a t Columbia
University Studio for the Pl'oduction of
T a pe Music
Peter Mauzey, Dept. of Electrical Engineerin g, Columbia University.
Sound Synthesis By The Use of Magnetized Arrays
A. H. Frisch.
Musical Timbre Mutation by Means of
the "Xlangumwandler," a FrequencyTranspOSition Device
Professor Vladimir Ussachevsky, Dept.
of Music, Columbia University.
Generation of Music by a Digital Computer
H. V. Mathews and N. Guttman, Acoustics Research Dept., Bell T elephon e
Laboratories, Inc.
Possibilities For Combining' Electronic
Music, Tape Music, and Musique Concrete with Traditional Music
Prof. Otto Luening, Dept. of Music, Columbia University.
Tuesday, September 30.
9:30 a.m. DISC RECORDING AND REPRO.
DUCTION.
H. E. Roys, RCA Victor, Chairman.
From Stereo Tape to Stereo Disc
Albert B. Grundy, Jr., International
E lectro-Acoustic Corp.
A New Master Disc Recording Lathe for
Stereo-disc Use
Stephen F. TemmeI', Gotham A udio Development Corp.
Recent Developments in Stereophonic
Disc Recol'ding'
C. C. Davis and Dr. John Frayne, Westrex Corporation .
Checking the Axes of Operation of Stereo
Cutter Cha nnels
H. G. Redlich, Teldec, Berlin, Germany.
The Ortofon Stereo Recorder
H. A. Arentzen, Ortofon Industries,
Copenhagen, Denmark.
1:30 p.m . DISC RECORDING AND REPRO·
DUCTION.
Benjamin B. Bauer, CBS L a boratories,
Chairman.
Some Thoughts on Geometric Co,n ditions
in the Cutting and Playing of Stereo
Discs and Their Influence OU the Final
Sound Picture
C. R. Bastiaans, N. V. Philips, The
Netherla nds.
A Stereophonic Varia ble Relucta nce Phonograph Ca rtridge
Peter E . Pritchard, G.E. Co.
The Development of a High-Quality Stereophonic Pickup Cartridge
Walter O. Stanton, Pickering & Co.
A Sing'le-Element Stereo Cartridge
John F. Wooel, Electro-Voice, Inc.
A Constant-Displacement Stereo Cartridge,
William S. Bachman, Col umbia Records.
A Moving Coil Stereo Cartridge
Rein
Narma,
Fairchild
Recording
Equipment Corp.
Wednesday, October 1.
9:30 a.m. MAGNETIC RECORDING-TAPE,
THE MEDIUM.
Walter H. Erikson, R a dio Corporation
of America, Chairman.
An Investigation of Magnetic Drop-outs
Robert H. Carson, U. S. Naval Research
Laboratory.
50 Mylar T - A Film Especially Designed
fOl" Use as a Magnetic Tape Base
Lester R. Barton, E. 1. DuPont d e
Nemours Co., Inc.
M agnetic Tape Recording with Longitudinal or Transverse Oxide Orientation
Richard F. Dubbs, MMM.
The Noise in Magnetic Recording which is
a Function of T ape Characteristic
Philip Smaller, Ampex Corporation.
Signa l to Noise Problems and New Equa lization fOl' Magnetic Recording in Music
John G. McKnight, Ampex Corporation .
A New Devi ce for the Reduction of
Print-Through
Franl, Radocy, Audio Devices, In c.
1 :30 p.m. MAGNETIC RECORDING TECHNIQUES AND EQUIPMENT.
Walter H. Erikson, Radio Corporatim1
of America, Chairman.
Evolution of a Successful Spring-Driven
Broadcast-Qua lity Tape Reco'r der
Alb ert C. Travis, Jr., Broadcast Equipment Specialti es Corp.
Mapetic Recording of Audio FrequenCles
Chester E. Beachell, National Film
Board of Canada.
Optimum Recording Conditions for Low
Tape Speeds
Harold A. Johnson, J ene L. Papier, and
Verner Ruva ld s, Sh ure Brothers, Inc.
Electroma"onetic Efficiency of Magnetic
Recol"der Heads
Marvin Camras, Armour Res. Fdtn.
A Special Technique Applica ble to SlowSpeed T a pe Recording
R. J. Youngquist, MMM.
Thursday, October 2.
9:00 a.m. ANNUAL BUSINESS MEETING
9:30 a.m. MAGNETIC RECORDING-NEW
DEVICES.
Wal ter H. Erikson, Radio Corporation
of America, Chairman.
40
High Quality Reproduction of Magnetic
Ta,p e in a Cal"tridge
D. R. Andrews, RCA Laborato r ies.
A Magnetic Head for Stereo or Half Track
on Yo -inch T ap e
H. R. Warren, RCA.
Professional High-Speed Duplication of
the New Four-Track Stereo Tapes
R. J. Tinkham, Ampex ·Corporation.
A Magnetic Disc Recorder for Broadcast
Use
Georqe Singer, RCA.
A Magnetic Head for Gl"ooved Magnetic
Recording Discs
H . R. Warren, RCA.
Properties and Perfol'1llanCe of Magnetic
Rubber Recording Belts
William Fabing a nd R. R. Hartel, Clevite Corporation
1 :30 p.m. MEASUREMENTS AND STANDARDS IN AUDIO.
Sheldon 1. Wilpon, New York Navar
Shipyard, Chairman.
The Automatic Plotting of Cartridge Response
C. P. Germa no, Clevi te Corporation.
Standa rds - Stepchild in the Laboratory
Charles E. White, The Avco Manufacturing Company.
The ARP2 A New Instl·tune,n t for
Sound M easurenle,n t
Louis W . Erath, The Southwestern
Electronics Company.
D etermination of Absolute Recording Sensitivity of Ma"onetic Tape
E. D. Daniel and 1. Levine, N.B.S.
7:00 p .m. TENTH ANNUAL BANQUET.
Friday, October 3.
9:30 a .m. STUDIO EQUIPMENT
AUDIO APPLICATIONS.
Philip Erhorn, Audiofax, Inc., Chairman.
A Three-Cha nnel Ste,r eophonic Sound Reinforcement Mixing' Console
Philip Erhorn, A udiofax, Inc.
An Audio Console Designed fOl" the Future
A. C. Angus, General Electric Company.
Multi-Channel Stereophonic Mixer Console
William H. Miltenburg, RCA Victor.
A Packaged Equipment fo,r the Production of Tl"ue Reverberation
Wilhelm
Franz,
Elektromesstechnik,
Lahr, Schwarzwald and V. J. Skee, Electronic Applications, Inc.
The Development and Application of Synt hetic Reve'r beration Systems. (Demonstra tion) .
Lewis S. Goodfriend. J ohn H. Beaumont, Vanguard Recording Society
7:30 p.m. LOUDSPEAKERS-DESIGN AND
APPLICATION.
Abraham B. Cohen, Adva nce d Acoustics
Company, Chairman.
Two N&w Horns and Drivers (Covering'
High Frequencies)
Messrs. Levy, Matsuoka., and Brociner,
University Loudspeakers, Inc.
Analysis of a L-F Loudspeaker System
Peter W. Tappan, The Warwick Mfg. Co.
New High-Efficieu cy P. A . Spea k ers
Messrs. Levy, Sioles, Carlis le, a nd
Sharp, University Loudspeakers, Inc.
A New Approach to Vented Cabinet Design
Messrs. Sioles and Brociner, University
Loudspeakers, Inc.
A
New
Wide-Angle
Direct-Radiatol"
Tweeter
Adelore F. Petrie, G.E. Co.
A Novel Com.pact Ste,r eo Speakel' Syste'm
Emanu el Berlant, Stephens-Trusonic,
Inc.
A Definitive Loudspeaker System fOl"
Monitoring in Control and Audition
Booms
Wilhelm
Franz,
Elektromesstechnik,
Lahr, Schwarzwald and V. J . Skee, Electronic Applications, Inc.
AUDIO
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AND
•
SEPTEMBER, 1958
A
•
.'
•
III
CollarD
Every part of every
changer
is precision-engineered to meet the rigid demands of Stereo
The new stereo r ecord s require a higher standard
of performance from your r ecord changer than do
standard LP's because stereo cartridges are extrasensitive to noise. That's why, in planning your stereo
system, you begin with the Collaro. Every part of
every Collaro changer is pl'ecision-En gineered to
mee t the rigid quality demands of stereo.
The motor (see A above) is dynami cally balanced, so rigidly mounted that wow and flutter speci·
fications are superior to any changer.
The spindle assembly (B) reflects this precision
quality in every part. The spindle itself is micropolished for complete smoothness.
The sensitive velocity trip mechanism (part shown
AUDIO
•
in C) has been designed so that the changer can
trip at extraordinarily light tracking pressures.
The exclusive Collaro transcription· type tone arm
CD) with the new plug-in h ead (E) is designed to
eliminate all resonances in the audio sp ectrum. The
new four-pin head- the only high fid elity changer
with this feature- provides the ultimate in noisereduction circuitry_
There are three Collaro changers ranging in price
from $38.50 to $49.50. No matter which you select,
you're sure to start yo ur system off right when you
choose Collaro- the turntable that changes r ecords.
For new Collaro catalog write to Dept_ A-9, Rockbar Corporation, Mamaroneck, New York.
Rockbar
is the American
sales representative
for Collaro, Ltd.
41
SEPTEMBER, 1958
www.americanradiohistory.com
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Equipment Review
Madison-Fielding Series 330 Stereotuner and Series
320 Stereo Amplifier-Harma n-Kardon F-10 FM Tuner
MADISON FIELDINC
SERIES 330 STEREOTUNER
With the gr owing number of FM-AM
stereo casts, demand has increased fo),
tereotuuers- separate AM and FM tuners
on a single chassis_ Today in approximately
two dozen cities there are affiliated FM and
AM stations that are stereocasting on
schedules ranging from one-half to 20 hours
a week One of the newcomers to the still
slende r ranks of ster eo tuners i s t he MadiSOil Fielding Series 330 shown in Fig_ 1.
This unit has four output jacks, which
supply the following signals:
1. FM, for feeding the FM signal into
the left channel of a stereo amplifier.
2. AM, for feeding the AM signal to the
right channel of a stereo amplifier.
3. AM/ FM, for feeding either the AM
signal or the FM signal into a singlechannel amplifier.
4. Multiplex, which takes the FM audio
signal prior to the treble de-emphasis circuit for the purpose of supplying a multiplex adapter, which will be on the market
when mu ltiplex broadcasting becomes a
reality.
The Series 330 is neat and simple in appearance, with only three operating knobs,
one for AM tuning, one for FM tuning,
and th e third a selector switch with four
operating posi tions, as follows:
1. OFF.
2. AM: The AM sigual is connected both
to the AM/ FM output jack and to the left
channel output jack, marked FM. Moreover, although the instructions make no
mention of this, the FM signal is connected
to the right channel output jack, marked
AM. In others words, in the AM position
of the selector switch the channels are
reversed.
3. S'l'EREO: Here the FM signal is connected to the FM output jack and the AM
signal to the AM output jack.
4. FM: The FM signal is fed to the left
output jack, marked FM and to the AMI
PM output jack. There is no signal present
then at the AM output jack.
It would seem that the above variations
as to the signals that may be obtained at
the various output jacks would take care
of most needs of most stereo fans. Moreover th ere al'e level controls for the two
output j acks at the r ear of the chassis,
permitting outp ut levels to be brought at
loast approximately into balance. Exact
balance cannot be achieved, except for two
specific FM and AM stations because levels
differ among stations and, in the case of
AM, with signal strength.
FM sound is clean and, when A-B'd with
a comparison tuner of known characteristics seems to have the correct amount of
trebl~ de-emphasis. An appreciable number
of manufacturers of FM tuners succumb to
the temptation of using less than the required amonnt of de-emphasis, thereby imparting a false brilliance to the sound, a
brilliance which often does not wear very
'well npon protracted listening.
The FM circuit is on the whole simple
and conventional, with a few departures
from convention that make a favorable
difference. It employs a tuned groundedgl'id r .f. stage, a triode mixer and separate
triode oscillator, a triode a.f.c. ciI-cuit, two
i.f. stages, a liuliter, and a ratio detector,
which is no longer looked npon with disdain for use in first-rate tuners. One of the
things that sets the Series 330 apart is the
unusnally wide i.f. bandwidth, which is
355 kc at the 3-db-down points. This helps
keep distortion low and accou nts at least
in par t for the clean character of the
sound. Alignment can be performed without r emoving the bottom plate, so that this
does not raise the problem of alignment
changing when the bottom plate is pnt
hack. Sensitivity is high, a nd a 3-foot
strand of wire appear ed to work quite
satisfactorily at a distance of 30 miles
f rom a number of FM stations. A.f.c.
action is quite moderate, just enough to
overcome drift but not so much as to
complicate seriously the problem of select-
fig . 1_ Madison-fielding Series 330 Stereotune r.
42
ing a weak station adjacent to a stl'ong
one. Use of a tuning eye- half of a 6AF6
(the other half is used for the AM section)
-facilitates tuning, and the point where a
station comes in best coincides with maximum closure of the eye.
All in all, the FM tuner appears to be a
very satisfactory unit.
.
While in the main the same can be saId
of the AM tuner, the latter does r aise one
serious question, that of adequate treble
response. Many AM stations transmit a
wide r ange signal, extending in a number
of cases to 10,000 cps, 12,000 cps, or even
higher. The limitation on frequency response, therefore, often lies in the AM
tuner. The Series 330 appears to have what
is often called "typical AM sound" so far
as freq uency response is concerned. This
reviewer tuned t he AM section of the
Series 330 to a New York City AM station
known to transmit a wide-range signal, and
there was a very decided difference between the signal r eceived on t he AM section of the tuner and the signal received ou
the FM section, which was tuned to the FM
adjuuct of t he station_
Otherwise, there appears little if anything to critici ze. Within the limitations of
frequency response, sound is clean, attributable in part to the use of a separate
diode for a .v.c_, thereby minimizing distortion. Also, the use of a separate diode
makes the a .v.c. action more effective, so
that the volume level is more constant
from one AM station to another.
Cathode-follower outputs are used for
both the FM aud AM sections, permitting
long runs of cable to the stereo amplifier.
Flywheel tuning facilitates station selection. '1'he ullit has a low silliouette and, as
previously r emarked, is good looking ; it
becomes even more handsome when installed in the natural wood finish cabinet
available at extra cost.
K -25
MADISON FIELDINC
SERIES 320 STEREO AMPLIFIER
The sudden ourush of stereo due to the
emergeuce of the stereo disc doubtless has
caused amplifier manufacturers to do a
good deal of deep t hinking. In designing
an amplifier for stereo, there is much room
for the display of imagination, originality,
and ingenuity, for there ar e many ways in
which the alllplifier can provide for controlling the stereo channels, coordinating
them, and permitting their use for monaural as well as stereo sources. The Madison
Fielding Series 320 amplifier r eflects a
good deal of serious and imaginative thinking as to the problems that the audiofanor r ather stereofan- is apt to encounter.
The Series 320 includes a control amplifier (tone, gain, loudness, selection) and a
power amplifier, rated at 20 watts, for each
channel.
The 320 is as much interested in providing mona ural l service as stereo serviceafter all, most of us will still want to keep
playing our treasured LP's and to keep
listeniug to single-channel FM until multiplex comes along. To this end, the selector
switch has duplicate sets of positions, one
set to the left of the center position, and
the other to the right. When turned to the
left (where there are three positions
maTked tape, tuner, and pTeamp), the amplifier becomes a mouophonic device, causing allY iuput fed to the left channel also
to be fed to the right channel. Inputs to
the right channel are t hen disconnected.
When the selector switch is turned to any
position to the right of center (again
there are three positions marked tape,
1 The term monaur aI is used here instead
of monophonic because the former is the
term used on the panel of the Series 320.
AUDIO
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•
SEPTEMBER, 1958
Enjoy stereo high fidelity now or plan for
it later using the versatile
Quartet
ALlEE
344A
monaural amplifier.
With the ALTEC 344A the conversion to stereo
is simple and inexpensive. All you need is
ALTEC's ingenious, new
S40
Master Stereo Control and a
second
Quartet amplifier.
The remarkable ALTEC Master Stereo Control, priced at just $12.00,
simply plugs in to the 344. It provides master channel control for both
Quartet amplifiers which can be used together for 40 watt stereo high
fidelity from tape, records or radio, or singly for 20 watt monaural play.
If you already own an ALTEC 344A Quartet you can use it for stereo
conversion anytime. All Quartets have been pre-engineered to
accept the ALTEC S40 Master Stereo Control.
You have all of these control
features for each channel
with the Al TEe 344A Quartet
stereo amplifier system.
Six Inputs - V.R. phono, tape deck, microphone, radio
tuner, tape machine, high level phono.
Four Major Source Volume Controls allow you to pre·set
and balance the level of any major program material and ,
change from input to input or turn the power on and off
without readjustment.
D.C. powered program indicator lights for completely
hUm·free operation.
Learn how you can
convert simply and
inexpensively to stereo
high fidelity with the
S40 Master Stereo
Control at your local
ALTEC dealer or write:
4 Position Contour Control for undistorted listening with·
out loss of extreme high and low frequencies at low
levels.
Separate bass and treble controls.
Three Position independent rumble and scratch filters.
Tape Recording Output - provided so material from any
input may be selected for recording.
Guaranteed Performance Specifications: 20·22 ,000 cps
range, 20 walts (40 peak), 138 db gain, 32 db bass control range, 35 db treble tone control range.
Prices: S40 Master Stereo Control $12.00
.. 344A 'Quartet $111.00 . . ..
Walnut, blond, or mahogany cabinet $19.50
ALTEC LANSING CORPORATION, Dept. 9A·A
1515 S. Manchester Avenue, Anaheim, California
161 Sixth Avenue, New York 13, New York
AUDIO
•
43
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
tuner, and preamp ) , then th e inputs to each
cha nnel are norma lled thro ugh; tha t i s,
inputs to the left channel go through the
left channel amplifier, aud inputs to the
right channel go through the right channel
amplifi er. In short, when the selector swit ch
is right of center, the Series 320 is a ster eo
amplifier.
Unlike the ma jority of st er eo amplifier s
- although ther e ar e other exception s in
th e same r espect-th e Ma dison Fielding
Series 320 does not have a balance control.
Inst ead it r elies upon sep arate g ain con·
t roIs f or ea ch cha1mel to achieve b alance.
Concentric with each g ain control is a
switch that converts th e form er into a loudness control. Like all ster eo amplifier s (at
least all thi s r eviewer has come across) ,
the Series 320 has a mast er gain control
t ha t governs both channels simultaneously .
One of the most intrig uing and n ovel
fea tures of this amplifier is the m eans
provided for achieving b alance b etween
channels, employing th e aid of a dual
magic eye tube, a 6AF6, each half of which
is similar to the familia r 6E 5. A built-in
tone genera tor is switched to each power
amplifier by mean s of a control ma rked
CALlBltATE. The output f rom each power
amplifier goes to half of a 12AX7 a nd
t hence to one of the grids of the 6AF 6,
ca using the eye of each h alf of t he electron
my tube to close p artially or fully. The
ext ent to which the eye closes is det ermined
by a potentiomet er ma rked POW E R, which
is concentric with the switch ma rked
CALIBRAT E . There is a set of power and
calibrat e controls for each channel. The
power controls are set to the same position,
according to p anel m arkings for 1 watt,
5 wa tts, 10 wa tts, 15 wa tts, and 20 watts.
The list ener may choose any panel ma rking
he desires, provided both power controls
are turned to the same position. This
mea ns that each half of th e 6AF6 will responrl in th e same f ashion for equal
amo unts of power supplied by each power
amplifier. Th en the gain cont rol of th e left
cha nnel is a dvanced until the left eye
sha dow of th e 6AF6 ba r ely closes. The
gain control of th e right channel i s similarly a dvanced until the right eye sha dow
barely closes. With the eye p roducing equal
indications in each section, there should be
equ al power output by each amplifier .
Th e tone controls are separ a t e for each
ch annel instead of b eing ga nged, as i s
mor e f requently the custom. For the left
channel there is a concentric pair of bass
an d treble controls ; a nd the same f or the
right ch annel. There a r e op posite schools
of thought as to whether g anged or sepa r at e controls a re most desirable, a nd this
r oviewer is 011 the fence b etween . Ganged
controls mak e for simplicity of appear ance
and operation, a nd since ma tched speakers
a re necessary for opt imum st ereo results,
there is a good case f or the ganged control.
On the other hand, ma ny st ereofa ns wlll be
lI sing differ ent speakers for t he right and
left channels, a t least initially, and in this
case sep a ra t e tou e controls may well be
desirable in Ql'der to allow for th e val'iation
ill fr equency r esponse of each speaker syst em. Even wh en matched speakers ar e employed, it is quite possible tha t differ ences
in their room locatio n will call fo r differ ent
amounts of tone correction.
Although th e Series 320 is r ated at 20
watts, it was f ound that a t 1000 cps i t
clip ped at a bout 14 watts on each channel.
This may be due t o th e use of EL84's in
th e output tube socket s in st ead of the
6BQ5A's desig nated on the chassis. Ac·
cording t o t he manufacturer, t he 6BQ5A's
will prod uce somewhat higher p ower under
th e same oper ating conditions. In any
event, th e difference between 14 and 20
wa tts is a ma tter of only ab out 1.5 db ,
which i s f a r fro m serious. It was f ound
t ha t each channel could t urn out a goo d
deal of p ower a t very low f requencies,
which is not true of all amplifier s tha t
tum out 14 watts or so at 1000 cps. 'l'hus
at 30 cycles, clipping was n ot obser ved ou
a n oscilloscope unt il output r eached 12
watts.
The so und of t he Maclison Fielding
Series 320 may be described as sweet and
clear. The quali ty of the sound i s confirmed by 1M clistortion measurements,
using 60 a nd 5000 cps r especti vely in 4 :]
r atio. Measurements for the left channel
showed 1M of about 0.2 per cent at 1 wat t
equivalent sin e wave power , 0.3 p er cent
at 2 wa t ts, 0.4 per cent at 3 watts, 0.8 p er
cen t a t 5 watts, 1 per cent at 8 watts, 1.4
p er cent a t 10 wat ts, and 3 p er cent at 15
watts.
Sensiti vity of the Series 320 appear s t o
b e quite a dequate for all inputs. As measured on the left channel at 1000 cps with
all gain controls full on, the tun er and t ape
amplifi er ( high level ) inputs r equired 270
mv for 10 wa tts out put, the t ap e head input r equired 2 mv, a nd the mag netic phono
illp ut r equired b ut 3.6 mv. Th e right
channel had abou t 2 db mor e sensit ivity,
but of course th e user would correct f Ol'
this b y means of t he individual g ain cont rols f or each channel.
Equalization appear ed t o b e quite accura t e on th e magnetic phono input a t th e
low end, b eing within 1 db of th e RIAA
cUl" ve at 50 cps; at th e high end, however ,
treble cu t was some 4 db less than stipula t ed b y RIAA. I n t he case of a signal
taken directly f rom a tape head, b ass
equalization was consider ably short of t he
N ARTB curve, wit h only 15 db boost
Fig. 2 . Harman -Kardon · Mode l F- 10 FM Tun e r.
44
supplied a t 50 cps instead of 23 db , using
1000 cp s as the refer ence point. Above
1000 cps th e NARTB curve exhibits about
10 db cut out to 15,000 cps, and th e Ma dison Fielding appear ed quite accura t e in
t his r espect.
It would be unfair to omi t f rom this
ext ensive discussion of the Series 320 some
mention of the yery h andsome cabinet
which is a vaila ble for the amplifier a t
moderate extra cost. The cabinet is in a
n atural wood finish . The amplifier complet e with cabinet has a low siThouette th a t
makes i t attractive a n d suitable fo r t ablet op or b ooksheld use, assuming adequat e
ventila tion is provided in t he latt er case.
K-26
HARMAN - KARDON F- l0
FM TUNER (THE TEMPO )
At a high enough price almost a ny thing
can be ha d in th e way of a udio equipment
-for example, a power amplifier producing
200 watts at less th an 0.1 per cent distortion. B ut the co=onsense approach i s
to dr aw the line fo r a p ar ticular component, a line above which no significant inC1'ease in pleasure or convenience l"esults
f r om a dditional dollars spen t . Of course
t he lin e varies with the individual, depending upon his t ast es, hearing acuity, p ocket·
book, and t he quality of t he r est of his
a udio equipment.
For t hose living in mb an a n d suburban
a r eas within easy elist ance of F M stations,
t her e is little or no neeel for an extremely
sensitive FM tuner. A t uner of normal sen·
sitivity can save th em mon ey. A dditional
savings can be had if they ar e willing t o
sacrifice some of t he f eatures found in
higher priced tuners, s uch as variable aLc.,
variable sensitivity, t uning met er , and so
on. On t he oth er ha nd, 110 comp r omise
should be t olerat ed with r espect t o the essentials, n amely clea n sonnd and st able
oper ation.
The in dividual seeking g ood FM r eproduction b ut willin g to a ccept some comp romises in order t o keep cost down will
find the H al"m an-K ardon F -10, Fig. 2, of
in ter est. T he design is alon g souuel, str aightforwal"d lines, an d t he tuner correspoudingly offers clean sound and simple opel"a ·
t ion. Si.x t ubes a n d a seleuium rectifier a r e
used. The f ront enel has a t uned triode
amplifier of grounded grid config uration
f or low noise. Th er e a r e t wo i. f . st a ges,
one limiter , and a F oster-Seeley cliscriminat Ol", such as usually f ound in the higher ·
p riced tuner s. The discriminator has f a irly
wide bandwidth, 600 kc, to minimize the
consequ ences of drif t and off-st a tion tUlling. In conventional ma nner, a dual triode
is used as an oscilla t or and as a va riable
react a nce f or a.f.c., which is n ot defeatable.
Due to a .f .c., flywheel action of th e
tuning k n ob, and a 0- 100 logging scale,
tuning is f acile. Station s snap in a nd out
with very little un certainty as on e g oes
a long th e dial. One or two t wirls of the
t uning kn ob t ake one clear acr oss t he elial.
Ou th e ot her ha nd, the dial is somewhat
on the small side, so that in section s of the
country with a g ood man y FM st a tions,
some stations may ap pear quite cr owd ed
on cert a in parts of t he dial. Never theless,
even t hough AFC is .not defeat a ble, no
difficulty wa s experien ced by t his r eviewer
in dialing close·togeth er sta tion s of con·
sider ably different signal strength, provided one t uned slowly . A.f.c. action i s
broa d enough f or t uning ease, yet not t oo
broa d.
S ensitivity is good, adequa t e for all bu t
the fringe a rea listener or the DX'er , with
t he high end of the clial somewhat the
more sensitive. Compa red with a high g ain
tuner having three i.f. sta ges and two
(Conti nued on page 47)
AUDIO
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AmericanRadioHistory.Com
•
SEPTEMBER, 1958
ELECTRONICS
IN
BRITAIN
STEREO STEREO STEREO STEREO
12W high slope
miniature pentode
This m edium power, high fidelity tube is particularly suitabl e for
ster eo equipment. Its high slope of 11,300 [.l mhos allows two EL84s
in push-pull to give over lOW output power at less th a n 1% distort ion
-all achieved for only 16V of grid to grid drive.
Th e EL84 m ay a lso be used for th e more economical higher pow ere d
equipments. Two tubes will provide an output of up to 17W at an
over a ll distorti o n of 4%.
A singl e EL84 will provide an output of nearly 6W. It h a s a maximum
pl at e dissipation of 12W.
Typical performance details for this tub e a re given here-for further
information a nd supplies write to one of th e distributors listed below.
MEDIUM
POWER
I
I
Distributed load conditions (scree n grid
HIGHER
POWER
I
Two valves in class AB push pull
taps at 43% of primary)
300
Va
300
V
Ik(ol
Ik(rn ax .sig.)
2 x 40
mA
2 x 45
mA
Rk (per valve)
270
n
V g2
V in (g l-g/) r.m .s.
R a _a
Pout
D eet
16
8.0
11
0 .7
Supplies available from:
In the U.S.A.
International Electronics Corporation
Dept.A9. 81 Spring Street. N.Y.12.
New York. U .S.A.
In Canada
Rogers Electronic Tubes &
Components
Dept. HI . 116 Vanderhoof Avenue.
Toronto 17. Ontario. Canada.
AUDIO
•
V
V
kn
V.
V g2
Rk
R. _.
la(o)
la (mag. sig.)
1' 2 (0)
I g2 (rnax. sig.)
W
Vin (g l_&l) r.m. s
%
P ou t
D eat
300
300
130
8.0
2 x 36
2 x 46
2 x 4 .0
2 x 11
20
17
4.0
Mullard
ELE CTRON leT UBE S
V
V
n
kn
rnA
rnA
rnA
mA
V
W
%
used throughout the world
" Mulfard" is the Trade Mark of Mulfard Limited and is registered
in most of the principal countries of the world.
I~I
MULLARD OVERSEAS LTD, MULLARD HOUSE, TORRINGTON PLACE, LONDON. ENGLAND
SEPTEMBER, 1958
45
www.americanradiohistory.com
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Seoudh ,4lUtUaJ
Chicago High Fidelity Show
and Music Festival
First major show of the season bows in at the Pal~er Ho~se
on Friday, September 19, for a three-day stay. ~adlo Station
WBBM-FM cooperating with suitable demonstration programs.
OR THE ~'lRS'l' TIM~ in H~-Fi.Show history, a local r adlO statlOn IS co-op~r ­
ating with the show management WIth
programming designed , especiall:r to serve
as excellent demonstratIon matenal for t he
high high fidelity equipment on display,
WBBM-FM, Columbia B roadcasting System affiliate in Chicago, will feat ul'e a
"block concept" of programming d uring t he
show, alternating light and classical music,
with hourly news broadcasts, and program
listings will be distributed in ad vance so
exhibitors may demonst rate their equipment
with the type of music t hey choose, according to information received from S. I.
Neiman, Show manager. Advance p~blicity
over the stat ion itself has resulted III ove l'
5000 inquiries f r om interested listeners as
to the Show and the equipment to be exhibited.
In addition to its prograIDIDing co-operation WBBM-FM- which, with its television' and AM radio affiliates blankets the
Chicago land trading area- plans a . hospitality suite and varions demonstratIOns at
the Show. A special staff of engineers and
announcers, independent of t he AM and
TV affiliates, has been set ul? .by WB~M­
FM to best serve the more-cntIcal r eqUIr ements of t he typical FM listener.
F
Just published.
The 4th Aud'io Anthology is n;ady for
shipment. 144 pages of complete articles by world-famous authors . . . contains everything from transistors to
speakers. Numbers I, 2, and 3 of the
AUDIO ANTHOLOGY are valued
highly in reference libraries throughout
the world ... Number 4 of the series
promises to provide the same quality
of articles th at has made the AUDIO
A NTHOLOGY a pri zed reference
work among the countless audio and
high fi delity enthusiasts, students, engineers and musicians. $2.95 postpaid.
SPECIAL OFFER!
If you 've missed the 3rd Audio Anthol-
ogy ... here is a wonderful opportunity
to get it for your reference library at a
savings of 60 %!
As a special offer .. .while they last...we
will send you th e 3rd A udio Anthology
o nly $1 when you order your copy
0/ the new 4th A udio Anthology. (This
/ 01'
offer good only while the small supply
las ts. )
RADIO M4GAZINES, INC.
Dept. AA34
PosfOffice Box 629
Mineola, N'e w York
[] Enclosed is my remittance for $2.95.
rle~ se' /end me a copy of the 4th A udi o
Anr-t!'o.lf;'gy; postpaid.
o :E'ncl.Qs'eil is my remittance for $3 .95.
Please 'S.~ nd me BOTH lhe 3rd and 4tlz
" A udiir':4 illlz ologies. postpaid.
Selling "Before and After"
Another form of co-operation is being
developed t o mer chandise high fidelity agg r essively "before, during, and after" the
Show itself. Th e Chicago Tl'ibune, the
Show management, trade gro ups, and local
radio and TV stations are working t ogether to promote high fidelity- as well as
the Show-to the thousands who will attend, long after t hey have seen and heard
what the exhibitors have to offer.
"While we have been successfnl at each
of our annual shows in bringing huge
crowds to the Palmer House, there has always remained the question of followin g
t hro ugh and selling t hese prospects aftel'
t he show is ove l'," saicl Neima u. "Last year,
one exhibitor used a f ull-page adver tisement in The l ' j'ibune t o illustrate many of
t he products clisplayed at the Show, listing
prices and details. Sales were phenomenal,
the firm reported.
The plan for this year i s for the newspaper to run a supplementary section immediately after the Show- sort o~ a "Post
Hi-Fi Show Section"- to say III effect,
"Now you've seen and heard everything in
hi fi-here's wher e to buy it and here's
what it costs."
Dealers have thus t hree fronts in which
to clinch the interest in hi fi- the pI'e-show
sections in T he T ribune and advance progr amming on radio and TV, t he Show it·
self, and t he follow-up which tells. the
p eople where they can purchase the Items
th ey saw and heard. With this tech nique,
Chicagoland is likely to bll. ,~uch mO.l'e hi-ft
conscious after the event t han It was
befo re.
Show a Sellout
As of Aug ust 15th, a' total of 134 rooms
were under contract, with only four suites
and a scattering of individual rooms still
46
available. As of press time, the following
exhibitors ar e scheduled:
AUDIO Magazine
ABC-Paramount Records
Acoustic Research, Inc.
Admiral Radio
Allied Radio COl·p.
American E lectronics, Inc. (Co nce rtone)
Amperex E lect ronic Corp.
Ampex A udio, I nc.
Audio Fidelity Recor ds
Aucliocmtt and H igh F'idel'i'ty Magazines
Bell Sonnd Systems
Ber cr aft
David Bogen Co.
R,. T. Bozak Sales Co.
Brit ish I ndustries Corp.
Custom Hi Fi
De Haan
E I CO
E lect ro-Voice, Inc.
Extron
Fishel' Radio Corp. (Fellieson )
Glaser-Steers Corpor ation
Grado Laboratories, Inc.
Gr undig Majestic
Harman·Kardon
Heath Company
H i F i Co. and Electrola
(Magnavox sponsored)
I n tel'lla t ional Electronics
Jensen Manufactnring Company
James B. Lansing Sound, I nc.
Lyon & Healy
Don McGohan
McIntosh Laboratories, Inc.
Magna E lectronics
Magnavox
Mastel' E lectronics
Mercury Records
Newark E lectric Company
North American Philips Co., Inc.
Olson Radio Warehouse
Oxford Comp onents
P etersen Co. '
Philco Corp.
Pilot Radio Corp.
Precision E lectroni cs (Gromllles)
Radio Corporation of America
Radio-El ectl'onics magazine
Radio Station WBB M-FM
Radio Station WEFM
Record Distrib utors
Rek-O-Kut Co., Inc.
Revere Camer a Co.
Sampson Company
Sargent-Rayment Co.
Schwartz-Woodlawn
H . H. Scott, I nc.
Sherwood E lectronic L aboratories
Oren H . Smith
Sonotone Corp.
Stromberg-Carlson
Superscope, I nc.
Telefunken
Thorens Company
Umbenhuer Co.
U niversity L oudspeakers, I nc.
Viking of Minneapolis
V-M (Voice of Music)
Wellcor
Westinghouse E l ectI:ic CDlp.
Wilcox Gay
W ollensak Optical Co.
Zenith Radio Corp.
AUDIO
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•
SEPTEMBER, 1958
EQUIPMENT REVIEW
([1'om page 44)
limiters, it brought in all the stations in
the New York City area (at least 16) just
as well from a distance of 30 miles, using
an outdoor antenna. Only when reaching
for stations considerably more than 30
miles distant did the F A-IO show signs of
falling behind the compar ison tnner.
A 36-in. piece of wire is supplied with
th e F A-IO as an iudoor antenna, and it
performed surpl'isingly well in picking up
stations 30 miles a way, leaving no doubt
that it would be quite satisfactory in an
urban location. However, much better reo
sults were obtained with an outdoor antenna. Alt hough the instructions state,
"Your TV antenna is not recommended,"
excellent reception was obtained by connecting to a TV wideband antenna. Appa r ently it is the narrowband TV antenna,
cut for one p articular channel or group of
adj acent channels, tha t is not r ecommended.
True, still better r esults can probably be
obtained by the fringe listener if he follows th e manufacturer's suggestion that
" A good FM dipole or yagi is worth the
investment." At the same time, he shonld
not be frightened away from nse of his
TV antenna, if it is a wideband t ype,
which he can easily connect to the t uner
by a simple switch and a few feet of 300·
ohm fiat wire.
Noise and hum of the FA-IO appear to
be as low as one could ask for. At reasonable volume levels when receiving stations
of normal strength, noise and hum produced by the t uner were not discerniblesuch noise and hum as were heard could be
traced to the station. Between-station noise
i~ q uite modera te at reasonable levels,
without great rushes of sound as stations
suddenly come in 01' go out.
Stability is excellent. Hannan-Kardon
claims drift of only ± 5 kc, and t his observer has no cause to dispute it. A station
would come in a t the same point on the
dial wh en the tuner was first turned on as
when it had been on a n hour.
The inherently good design and construction of the FA-IO is evidenced by its low
distortion, which the manufacturer claims
to be less than 1 per cent harmonic and
less than 1 per cent 1M a t 30 per cent
modula tion. On a signal of normal strength,
this reviewer measured only 1.2 per cent
IM distortion at full modulation (he has
measured 4 or 5 per cent on much higher
priced tuners); and only 0.25 p er cent at
30 per cent modulation.
However, these are minim um IM figures
ob'tained by tuning for lowest distortion
as observed on the IM met er . Since there
is no tuning indicator, the user cannot
tune exactly to the station for minimum
distortion. About the best t hat he can do
is to tune to a spot on the dial half way
between the points where the desired station snaps in and snaps out. Thus at full
modulation, by this "half way" method,
2 per cent 1M was obtained instead of t he
possible minimum of 1.2 per cent; at 30
per cent modula tion , th e "half way"
method resulted in 0.45 per cent 1M instead of 0.25 per cent. All in all, careful
tuning can produce very good results on
normal signals, probably indistinguishable
from the sound obtained with th e aid of an
accurate tuning indicator.
The sound of t he FA-IO, already described as clean, has a light, incisive quality which may be ascribed to the use of
appreciably less than t he 75-J.tsec de·
emphasis stipula t ed by t he FCC. Utilizing
AUDIO
•
The owner of a Fairchild Stereo Cartridge takes justifiable pride in its possession, for it refl ects
in tangible form a quarter century' s consistent policy of building up to a high quality standardcost r emaining a secondary consid eration.
.
He is sure that the new Model 232 Stereo Cartndge I S an lllves tment III the finest record
reproducti on-both stereo and monaural. H e knows that its superb performance is the natural
result of advanced engineering -the very same engi neering which produced the first Stereo
cartridge ever demonstrated to the public (December 195 7) . Its phenomenal tracking ~ b ility ,
absence of distortion, and gentle trea tment of records, are taken for granted by the Fairchild
owner, although they are often a revelati on to those accustomed to ordinary cartndge performance. Its transparent, shimmering sound quality, so fai thful to the original, as well as its full
range channel separation, are further evidence of Fairchild 's engi neering leadership .
Therefore, he is not surpri sed to learn that many majo r recordi ng stud ios are using Fairchild
cartridges to test the quality of Stereo and other high fid eli ty r ecordings. H is pride of ownership,
in short, stems from the add ed satisfaction which only a quality product can provide, and from
his secure knowledge that the name Fairchild is synonymous with integrIty of manufacture.
Price of this superbly engineered cartridge . .. $49.50.
H ear the S tere o 282 at your hi-fi deale1·. Write fo r boo klet [(-1, t he complete Stere o Disc St ory,
FAIRCHILD RECORDING EQUIPMENT COMPANY
10-40 45th Ave., L. I. C. 1, N, Y.
Fairchild "Sound of Quali ty" Component s include :
car t1'idges, arms , turnta bles, pre-ampli fi ers and amplifiM's ,
47
SEPTEMBER, 1958
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AU D I 0
ENGINEERS'
SHOW
Audio
Engineering
Society's
1958 CONVENTION and EXHIBITS
at
th e
HOTEL
NEW
YORKER
34th Street at Eighth Avenue, New York City, New York
Showing Professional Audio Equipment
for Studio and Laboratory
SEPT. 29, 30, · OCT. 1, 2, 3
a 22K resistor and a .002·!-tf capacitor, the
deemphasis network has a time constant
of only 44 !-tsec. Adding the capacitance
of the cable supplied for connecting the
tuner to an amplifier a nd of the probable
input capacitance of the amplifier, the
time constant rises to about 50 !-tsec, reo
suIting in treble droop with a turnover
f requency (3 db down) at ab out 3200 cps
instead of 2120 cps. The result is treble
boost, reaching somewhat more than 3 db
at 10 kc and larger amounts at higher
frequencies. Sufficiently accurate deemphasis could be obtained by placing a .001-l-tf
capacitor across the signal either at the
output j ack of the tuner or the input jack
of the following amplifier.
lE
AUDIOCLINIC
([1·01Th page 4)
When an amplifier is turned off, the
lines of force collapse about the turns of
the secondary of the power transformer,
causing the voltage across this winding to
rise momentarily to a value cons~derably
higher than that of normal operation. This
canses the amplifier to draw mOl·e plate
current. At the same time, t he higher voltage allows the filter capacitors to take a
greater charge, which means that even
more momentary cnrrent flows. Althongh
these fuses are designed to handle momentary surges, they nevertheless have
their limits. I recommend, therefore, that
you use a large fuse. Since the ratings of
these F usetrons are graduated in small
steps, I'm sure you can find one which is
sufficient to handle the overlo ad peaks, and
still provide protection.
lE
AMPLIFIER
Psychoacoustics of Stereo
Transistor Application Problems
Magnetic Recording and Reproduction
Loudspeaker Design and Applications
Standards and Measurements
([1·0m page 23)
from this technique were as close to
those displayed in F1:g. 6 as resistor
accuracy and meter reading ability
would p ermit , in other words within
ahout 5 per cent.
Disk Recording and Reproduction
The "Unbalanced Bridge" Method
Music and Electronics and others
In an attemp t to refine this method
still further and measure the voltage
cha nge more accurately, a n unb alanced
bridge arrangeme nt was usrd (see F·ig.
8) . The philosophy here is that the
voltmeter reads E s [ O.S - Rz/(R, + R z )]·
Furthermore, if the two half-ohm resistors are not exactly equa l, theu: relative value lllay be established by initially balancing the bridg'e and noting
the reading on the decade potentiometer. This reading is then used in place
of 0.5 in the for egoing formula. Oneohm increments of the total load are
taken as above and each time the
bridge is unba lan ced enough to produce,
say, .01 volt. E3 is then compu tecl and
handled in the same maImer as the volt meter r eading in the preceding method.
This setup is perhaps the most ac ~ urate
but requires more elaborate equipment.
DAILY SESSIONS 9 :30 am & 1 :30 pm
Additi onal Mon . & Tues . 7 :30 pm
EXHIBITION HOURS -
Daily -
noon to 7 :30 pm
Runs concurrently with IHFM Annual High Fidelity Show
iD't09'tam. A(laiLadte l'tom
AUDIO ENGINEERING SOCIETY
P.O. Box 12, Old Chelsea Station, New York 11, New York
iii
W
48
AUDIO
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•
SEPTEMBER , 1958
The sighing wind ... the rippling water ... the roaring surf ... each voice clear
and distinct yet blending into the glorious symphony of the sea. This quality of
living natural sound can be yours to enjoy with High Fidelity by Grommes ...
the natural tone of each voice ... each instrument ... the sparklin g clarity and
rea listic depth of the live performance ... hi gh fidelity reproduction at its finest.
Grommes Hi-Fi components are craftsman-designed and assembled with jewel-like
precision ... built to last for years of musical enjoyment. Beautifully styled in
gleaming gold and white set in leatherette cases.
Visit your Grommes Hi-Fi Dealer . .. see and hear these exciting new Stereo High
Fidelity Amplifiers, Preamplifiers and Tuners .
••••••••••••••••••••••••••••• •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
o Please send - me Free Color
C;IIe-Ht"' e.L Div. of Precision Electronics, Inc. Dept. 0000, 9101 King St., Franklin Park, III.
Brochure featuring the new
Grommes Hi-Fi Series.
Name ____________________________________________________________
StreetL_ _ _ _ _ _________ _ City _ _ _ _ _ _ _ _ State: _ __ __
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AMPLIFIE R
Selected For Display
At The Vienna
THE · NEW
STROMBERGCARLSON
COMI{ONENTS
Integr
'n Music, as
applie
high fidelity
compo!') ,,gts, means reproduction which adds
nothingf to, or takes
nothing from, the original performance.
Stromberg-Carlson's
choice of this slogan is
no accident. Just as you r
purchase of a component sy.stem is not a
casual 'ririvestment, our
attitude't oward the manufacture of components
is very serious indeed.
Each piece of gear must
reflect the highest possible ach ievement of eng ineering, production,
and musical skill. The
guiding minds, hand,
and ears of the Strombe rg-Carlson component
group are those of professional electronic and
acoustic engineers with
extensive musical training .
The musical sound of
our new components
was the final critical test
before they were made
available to you.
We proud ly submit
our specifica ti ons to
your critical judgment.
These specifications a re
accurate and conservative. We have declared
ourselves out of the
"battle of exagge rated
specifications. " Please
study our specifications
to see how the phrase
"Integri.ty in Music "
takes on true life and
meaning.
International Fall Fair.
OUT
A.C.
VTVM
ASR-433
STEREO AMPLIFIER
Th e most important as pe ct of
st rum e nts of the orch estra
should com e bac k to y ou f rom
th ei r exact positi ons on the
stage. How?
Th e answer is balance. The
ASR-433 is the stereo ampli·
fi er w ith "Tone -s;g nol Balonce," th e surest method of
achi evi ng thi s re al is ti c stage
effect.
Th e ASR·433 is a s uper b
monaural amplifi e r a s well,
g ivi ng you a full 24-wa tt output. Th e electronic crossover
at 3,000 cycl es provides output for 12 watts low and 1 2
watts hi g h frequency op era-
tion.
Every function ha s its
own co ntrol for eac h chann el
an d a master v olume control
is provided.
SPECIFICATIONS :
POWER OUTPUT, 24 walls
(2-12 wall channel s). FRE·
QUENCY RESPONSE , 20-20,·
000 cycles ± 1 db. HARMON IC DISTORTION, Less
than 1 %. NOISE LEVEL , 6 3
db down. INPUTS: Ma g neti c
Phono, Ceramic Phono, Tape
Head, Tun e r a nd Aux. Tape.
OUTPUTS. 4, 8, 16 ohms and
du al Tape Ou t. LOUDNESS
CONTROL , In -o ut , conti nuously variable. TONE CON ·
TR OLS , 8ass 15 db droop,
15 db boost; Trebl e 14 db
droop, 12 db boost. EQUALIZATION, RIAA Mag. Phono .
NAR TB Ta pe Head . TUBES ,
2-12AX7/7025, 2-6AV6, 26U8, 4·El 84 . CHANNEL SE.
LECTOR, C h ann e l "A ,"
Cha nne l "8," Stereo, Monau-
ra l, Cross ove r (at 3000 cycl es). DIMENSIONS, 13 1/,"
13 '/." D, 4%" H. PRICE ,
$129.95* (Audiophile Net).
w,
·A II prices are Zone I.
See your dea le r or write to
us for full data o n our comp lete new lin e of amplif ie rs,
speakers, speaker sys te ms, enclosu res and program sources.
STROMBERG-CARLSON
DIV I S ION
O F
GENERAL
1418C N. Goodman Street
Bridge method for accu rately
measuring small voltages.
stereo is stage effect. Th e in-
" There is nothing finer than a Stromberg-Carlson "
A
Fig . 8.
DYNAMICS
•
CORPORA TION
Roch ester 3, N. Y.
Electron ic and communication products for home, indu stry and d efense; incfuding Hi gh Fid e lity Consoles;
School , Sound, Intercom and Public Addre ss Systems.
50
No significant differences from previous
results were r ecorded here.
Seeking a somewhat more direct technique and noting that internal resistance
determines the POWM' change when the
load is changed, an accurately calibrated power output meter of the General Radio 583A or 783A and Daven
OP961 types were utilized. Two output
powers were r ecorded with two different
loads- in this case, 12.5 and 15 ohms
were the closest to the rated load. If we
assume that load RLI gives greater
power output that RL! (and thus
F R > 1) we can write:
(Ri,,~+Rlr RI
)2
E
( R int +R z R 2
Powm' output tvith load RLI
-----=---------,-,-= = P R
Powel' Otttput with load R Lz
Performing the necessar y algebra
R;.nt=
R IR z (P R -1) ± V PRRIR. (RI- B . )
RI -PRE.
Use the negative sign in the numerator
when the denominator comes out negative-positive when the denominator is
positive. The only difficulty with this
system (other than the thorny formula
above) is that the power meter indications tend to become unreliable at the
higher frequ encies, but below 10,000
cps r esults tallied with F ig . 6.
As a final check, it was decided to use
two frequency components-one coming
through the amplifier and one being run
through the output circuits- and measure them separately by means of a wave
analyzer (see Fig. 3). Make R =13
ohms and substitute a Jow-output-impedance signal generator for the Variac.
Note that the amplifier is correctly
terminated as the impedance of the
step-down transformer secondary is
extremely small. Thi s now corresponds
AUDIO
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•
SEPTEMBER, 1958
to a stol'ed-energy transient situation
as encountered in a udio amplifiers. The
impedance seen by the signal being fe d
back into the amplifier may be determined by simple voltage-division principles since we know the magnitude of the
voltage supply and the drop across a
known resistance. As long as we keep
within reasonable frequency bounds,
there will be no a ppreciable phase shift.
Suffice to say that the impedance seen
by this " backward" component is almost entirely a function of the magnitude and frequency of the sig nal coming through the amplifier in the normal
way. "Almost entirely" because it is
possible to create transformer satm ation with this driven current, but this
is scar cely likely to happen under normal amplifier usage. This, too, produces
a et of values within normal measurelIlent error of those displayed in Fig. 6.
Since many of these calculatio ns involve small differences between r elatively large quantities, it is mandatory
that the resistors, voltmeters and other
paraphernalia be accurate to one-half
of oll e p er cent 01' better .
IE
NEW SLIMLINE®SPEAKERS
Our speakers are completely revolutionary in performance . Our equipment and background in the
design and specifications of speakers are second
to none. We have put into words an exact descrip '
tion of the way they sound . .. so radically differ·
ent that a full explanation is necessary.
Full specifications are incorporated in a Stromberg-Carlson booklet explaining our concept of
speaker specifications and design. Ask your dealer or write to us for "A Revolution in Speaker
Specifications and Design."
REFERENCES
Richter, "Measuring amplifi er illtern a l
resistance. AUDIO E NGINEERING, October,
1948.
2 Mi tchell, "Audio a mplifier damping."
Elect?'onics, September, 1951.
1
3 W. L. Everitt, CO?n1l1unications Engi.
1lee1-ing (second Ed. ) . McGra w Hill, p . 568.
ApPENDIX
( Refer to F ig. 2)
E
E
RF-481 Slimline 12" Wid e
Range Diffusex Transducer.
$39.95 (AUDIOPHILE NET)
RF-482 Slimline 12" Coaxial
Transducer . $59.95
IAUDIOPHI LE NET)
RF-483 15" Coa xi al
Transducer. $99 .95
(AUDIOPHILE NET)
E O·/tt 2 =I ,R{'2
=IJR i nt + I JRLI =I 2R int + I ,R{'2
Eo"t 1
E
$24.95*
(AUDIOPHI LE NET)
RF-480 Slimline 8" Transducer.
I ' = R int + R-' 1'2
=I ,R L, ;
I ,R i nt
+ Eout 1 = I ,R;"t + E OUf2
R i"t ( I ,-I ,) =Eou f2 -E.ut ,
R.
_ E ou t 2 -E."t,
1,-1,
."t -
FEEDBACK
(f1'om pag e 32 )
nominal value, the damping factor of
the amplifier is 4, a value which provides good operation with most speakers. However, other damping factors
can be used, and while absolute isolation between load and feedback is not
obtained, a sufficient degree is r ealized
to be of positive benefit. For example, a
capacitive load will not display ringing
a t any setting of the controL Moreover,
the system has the beauty of sup plying
val'iable damping with insignificant increase in distortion, and maintains a
consta nt amount of feedback so that
output level is independent of the setting of the damping control. The C01l1 p lete schematic of the amplifier
shown in Fig. 2.
AUDIO
•
See your dea le r
or write to us for
full data on our
co mpl e t e n ew
line of amplifie r s, s peak e r s,
speake r systems,
e nclo s ures and
pro g ram sources.
RF-475 15" Coaxial ·Transducer.
$229.95 (AUDIOPHILE NET)
• All prjces are Zone I .
"There is nothing finer than a Stromberg·Carlson "
STROMBERG-CARLSON
A
DIVI S I O N
O F
GENERA L
1418C N. Goodman Street
OYNA MI C~
•
Ele ctron ic and comm unication products fo r hom e, in dustry and defe nse ; includin g Hi gh Fidelity Con so les;
School, Sound, Int ercom and Public Address Systems .
SEPTEMBER, 1958
CQRPO!=:A T 10N
Rochester 3, N. Y.
I
S-C GO
~ @: f
'\,~~:...,,,.
'~~
•....}
~
.. '
51
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STEREO RECORD
YOUR OWN SPECIAL EFFECTS
WITH THE AMPEX
UNIVERSAL llA" 960
NEW LITERATURE
• Lafayette Ra.dio, 165-0 8 Liberty Ave.,
J'a maica 33, N.Y., is now m a iling it s n ew
1959 general catal og of e lec troni c p a rt s
a nd eq uipm e nt, including a compl ete section d evoted to high-fidelity components.
Highlighting this section is a co mpre h e nsive li stin g of the n ewest stereo equipment, in cludin g compon ents for con vers i on of monophonic systems to stereophonic sound. A compl ete selection of
major-la b e l stereo di scs a nd r ecord e d
tapes is a lso li sted. An extensive publica ddress section li sts components as w e ll
as complete systems from a ll ma j or manufacture rs. The catal og contains 64 pages
in color, a nd h as the large 8" x 10" p age
Lafayette format. Your copy wi ll be
m a il e d free upon request for Catalog 59 0.
K-lS
• Pickering & CO'n lpany, Sunnyside B lvd.,
P la inview, N. Y ., is m a king availab l e a
n ew booklet written by J ean She phe rd,
well-kn own radio personality a nd hi-fi
h o bb y ist. "ISOPHASE--A New Kind of
Suund" i s a basic story of the e l ectrostatic speaker , written fo r the non-technical r ead e r in the erudi t e s t y l e for w hic h
Shepherd is n ote d. It offers delightful
reading for the enginee r a nd layman a like.
Your copy of thi s excelle nt bookl et w ill
b e m a iled free upo n r eq u es t t o D e pa rtm ent IB a t the a ddress s hown a b ove.
K-lS
• James B. Lansing Sonnd, Inc., 3249
Cas itas Ave ., Los Angeles 39, Calif ., d e scrib es a nd illustrat es the e ntire line of
Lansing !;;ound reproducers in a n ew
fo lde r w hi c h h as just been r e lease d . Illu str ated with som e 40 photographs,
d"awings a nd c h arts, the fo lde r in c ludes
data on wide-range speak e rs, low- a nd
hig h-f r e qu e n cy d r iv e rs, dividing n etworks
a nd
Now you can capture any memorable event in living stereo - with the new
Ampex Stereo Record Universal "A" Portable (Model 960). And in addition to "live" recording with microphones, you can record stereo off the air,
copy stereo tapes and discs and build a stereophonic tape library of truly
professional quality at lowest cost and with this single unit you can record
monaural sound-on-sound with full control of balance. This precision engineered, ruggedly constructed Portable stereo recorder/reproducer gives you
all the advantages of traditionally superior Ampex features. With the instantacting head switch, you can shift from 2-track to 4-track operation at will,
and play back as long as 4 hours and 16 minutes of stereo music on a single
reel of tape (2400 ft.). Automatic stop at end of reel. Also available is the
Ampex monaural recorder/stereophonic reproducer (Model 910). Performance will be within specifications the first day you own it and for many years
to come. Three precision dual head stacks (one each for record, playback and
erase) are Ampex designed and built to tolerances as close as 10 millionths
of an inch. The two Ampex (Model 2010) Amplifier-Speakers will complete
your stereo portable system. All three units are lightweight, durable and III
matched, smartly styled two-tone grey carrying cases.
AlVIPEX STEREO
SIGNATURE
OF
PERFECTION
IN
SOUND
I
AMPEX AUDIO INC.
1060-) KIFER ROAD . SUNNYVALE. CALIF.
I
Please selld me full illformation on the AMPEX STEREO
I
RECORD UNIVERSAL "A" PORTABLE SYSTEM (Model 960):
I
I
NAMEE:-_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
I
I
ADDRESS, _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
I
I
CITY _ _ _ _ _ _ _ _ _ _ _ _ _ _ ZON E _ _ STATE _ _ _ _ _ _ __
IL _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
52
var"ious
of
e n closures
a nd
• Bell Sound SystE>ms, Inc., 555 Marion
Road, Co lum bus, Ohio, is n ow releasing
a n ew 24 -page book l e t which is a h a ndy
r efer e n ce guide, with ph o tograph s, of
t h e compl e t e lin e of Bell high-fidelity
compo n e n ts. Detailed s p ecificati on s prov ide a complete directory of the perfo rma n ce c h aracteris tics of a ll unit s
s h own. Two special sect ions of the h a ndbook are de vote d to q u estio n s a nd a nswe r s abo ut high fide lity a nd s t e r eo, to
h e lp r ead e r s p la n their own in stall ations.
I n r e questing yo u r f r ee copy of t hi s interesting booklet, be s ure to spec ify
Cat a l og 101.
K-lS
• Ce.n tra1ab, A Division of Globe-Union,
Inc., 900 E. K eefe Ave., Milwaukee 1, Wis. ,
h as ju st released a revised version of the
Ce ntra lab b ooklet on the "Compentrol,"
a co mp ensa t e d volum e con trol for highfidelity mu s i c systems . Inte nde d prim a rily
as a r e place m ent unit fo r or dina ry v olum e
c o ntrols on radio a nd TV receivers, phonog raphs , a nd the lik e , the Compentrol
co mp e n sat es for t h e Fletcher -Mun son eff ect in hum a n h earing. Th e 20-page
b ooklet is profuse ly illu s tra t e d , a nd i s
avail a ble free of c h arge up on - w ri t t en
r eq u est.
K-l9
• ReE>ves Soundcraft COr}loration, 10 E.
52 nd St., New York 22, N .Y. , h as just
publi s h e d a bull e tin o n "Magn a -See," a
n ew solution r ecently d evel oped by the
Reeves firm which m a k es vi s ibl e the
so und track recorded on magnetic t a p e.
Magna-See Type SO (for sound recordin g ) enables th e recordist to m a k e f as t,
s imple and acc ura te equipment checks for
h ead a li gnment, trac k un iformity, bala n ce, a nd h ead wea r. The bulletin d e scribes, with illustrati ons, how the so lution should b e u sed. Requests for co pi es
s hould specify B ull etin RS-57-10.
X-20
AUDIO
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types
horns. A featured li sting is accord ed the
"Par ago n, " a n integrated stereo reproducer which i s th e n e w est a dditi on to the
Lansin g lin e. Be s ure to specify B ulle tin
SC - 504 when writing for your copy .
K-l7
•
SEPTEMBER, 1958
HEARING
([1'om page 36)
broadcasting but it should be kept in
mind when considering what improvements are possible in the quality of the
reproduced sounds.
In conclusion then, it is seen that for
an ideal system, one which is determined
by the capabilities of hearing, the maximum and minimum intensity levels and
frequencies will be determined by Fig. 3
and two or thTee channels should be used
in the transmission . With such a systell'
there will be no limitation upon the type
of material used in the broadcast. For
economic reasons we may back away
from these ideal requirements. Although
the best quality cannot be obtained with
a frequency range lower than 14,000 to
15,000 cps, economic necessity may require a compromise to a somewhat lower
frequency limit. The ideal volume range
for producing a facsimile of such music
is 65 decibels. How much this volurll e
range can be reduced below this value
without producing serious impairment
has not been determined in a quantitative way. There is no doubt that considerable improvement in quality will
also result by going' to two or more
channels instead of one, but whether
such improvement is worth the additional cost must be decided for each kind
of service in which the transmission system is used.
STEREO PLA VBACK
([1'om page 27)
problem exists the same head is used
both for recording and playback. The
writer rarely uses both sides of the tape
for single track work because he likes
to edit his tapes : consequenctly there i '
no cross-talk problem. Furthermore, the
use of separate heads permits the tape
to be monitored as it is being made, giving an audible indication of the quality
of the recording.
Unfortunately the Viking deck does
not have a second set of stereo heads
for monitoring stereo recordings off the
tape as they are being made. However,
a daptor units ar e available with the necessar y heads installed and these ar e designed for "outboard" mounting. Such
an arrangement would be decidedly
worthwhile and inclusion of such a device into the present system is contem plated.
This amplifier has been used to make
duplicates of tapes recorded in the usual
manner, both single track and ster eo.
Fortunately, the writer has been able to
borrow a second deck for this purpose.
One machine is used for playback, the
other for recording. The output of the
playback amplifiers are patched to the
input of the recording am plifier s. E xcellent r esults have been obtained. It has
AUDIO
•
FULL FREQUENCY
FEEDBACK
AMPLIFIERS
effe ct on all inputs. Has 3 positi on s. TUBES : on e 5V.4GA ,
one 6U8 , two 7025/12AX7, two
7027. DIMENSIONS, 13 ,/," w,
13 %" 0, 4 3/. " H. PRICE,
$ 119.95 *
All output tubes in our
new line operate below
their rated capacity. For
example, our 40-watt
power amplifier uses
output tubes rated for
1 DO-watt operation.
These amplifiers incorporate a new concept of
record equalization.
without
top
cove r
(Aud iophile Net).
AR-431 CONTROL AMPLIFIER
POWER OUTPUT , 20 watts.
FREQUENCY RESPONSE , 2020, 000 cycles ± .9 db at full
output. HARMONIC DISTORTION , Less than 1 % at full
output. 1M DISTORTION , Less
thon 1 %
program leve l. NO ISE
LEVEL , 65 db down . INPUTS ,
Magnetic Phon'o, Ceramic Phono , Tape Head, Tun er, Aux.
OUTPUTS , Ta pe, Amplifier (A,
4 , 8, 16, B) . SPEAKER SE LEC-
AR·430 CONTROL AMPLIFIER
POWER OUTPUT , 12 wall s.
FREQUENCY RESPONSE , 2020,000 cycles, ± 1 db . HARMONIC DISTORTION , less than
1 .5 % . NOISE LE VEL , 63 db
down. I NPUTS , Magnetic Phono, Ceramic Ph ono, Tape, Tun e r
a nd Aux. OUTPUTS , 8 ohm s.
LOUDNESS CONTROL In -au',
continuously
variable .
TONE
CONTROLS, Bass, 15 db droop,
15 d b boost; Tre bl e, 14 db
droop, 12 db boost. EQUALI ZATION, RIAA Mag. Ph ana.
NARTB Tap e Head . TUBES, One
7025/12AX7, one 6AV6, one
6UB, two 6B05/EL84, one
6CA4/EZ81. DIMENSIONS , 12 "
w, 5'/,' 0 , 4'/. " H. PRICE ,
$59.9 5 ' (Audiophil e Net) .
Price in cludes top cove r .
TOR SWITCH : Provides switching to one spea ker, a sec ond
speaker or
both.
LOUDNESS
CONTOU R: Tw o positions prov ide two differe nt levels of
compensation
in
accordance
wit h Fl e tcher-Mun so n curves.
TONE CONTROLS, Bass 22 db
droo p, 16 db boost; Tre ble 15
droop, 16 db boost . EQU ALIZA TION, Ad justme nt of RIAA
Recording Curve-Two slide
switc hes for high frequencies
and two slide switches for low
frequencies .
RUMBLE
Two-position switch.
FILTER,
In effe ct
on all inputs . SCRATCH FILTER,
Two-positi on switch. In effe ct
on 011 input s. TUBES : one 7025,
two 12AX7 , four BQ5. DIMENSIONS , 13'12 " W, 9'12 " 0 ,
4% " H. PRICE, $99.95' without top cover (Audiophil e Net).
AR-432 CONTROL AMPLIFIER
POWER OUTPUT, 30 walls.
FREQUENCY RESPONSE, 2020,000 cycles ±. 9 db a t full
output. HARMON IC DISTORTION , 0.7% a t full output. 1M
DISTORTION, Less 'han 1 %
program level. (60,7kc /4 ,1 ).
NOISE LEVel, 70 db down .
INPUTS: Magnetic Phono, Ceramic Phono , Tape Head , Tun e r,
Tap e, Au x . OUTPUTS, Tape,
Amp lifie r (A , 4, 8, 16 , B).
SPEA KER SELECTOR SWITCH ,
Provides sw itchin g to o ne spea ke r, se cond spe aker, or bo th.
LOUDNESS CONTOUR , Two positio ns provide different le ve ls
of compensation in accordance
with Fl e tch e r-Munson curves.
TONE CONTROLS , Bass 20 db
droop , 15 db boost; Tre ble 15
db droop, 15 db boost . EQUALIZATION , Adjustment of RIAA
Recording Curve-Th ree s lide
switches for hig h frequencies
ond three slide switches fo r low
fr equ e ncies .
RUMBLE
FILTER,
In effect on all inputs . Has 3
positions. SCRATCH FILTER , In
AP-437 POWER AMPLIFIER
POWER OUTPUT, 40 watts .
FREQUENCY RESPONSE, 2020, 000 cycles ±.1 db at 40
watts; 10-60,000 cycles ± 1 db
at 40 watts; 10-100,000 cycles
+1 db at 10 watts . HARMONIC
DISTORTION, 0.1% mid frequ e ncie s at 40 watts. 0.5 0/ 0
20·20,000 cycles a ' 40 watts.
1M DISTORTION, 0 .4% at 40
watts .
(60 ,7kc/4d J.
NOISE
LEVel , 90 db down. INPUT,
On e with variable input se nsi-
tiv ity from .7 to 10 volts. CONTROLS : Hum control, balancing
control, bias control. OUTPUTS :
A, 4, 8, 16, B. SPEAKER SELECTOR SWtTCH, Provi des
switc hing for on e speake r, a
second speaker, or bo th". TUBES
two 6550, one 12BH7 , one
7025, one 5AR4/GZ34 . DIMENSIONS, 10 ,/," W, 6 ';'''
H, 10" D. PRICE , $145 .00'
(Audiophile Net). Price inFor Full Dolo On Any And
All
Ite ms, S ee Your Dealer
Or Write Us Direct.
cludes top cover.
• All prices ore Zone t.
"There is nothing finer than a Stromberg-Carlson "
STROMBERG-CARLSON
I "LA:-..:D
: .;.'_~>.,:c.:. ..~:::...c: -=- F
G ENE R A LOY N A. M t
1418C N. Goodman Street
~~
."
_
cs ~
0 R P'O RAT ION
Rochester 3, N. Y.
s-c I.GO
~ .. "."-
. Electronic. and commun ication prod~d$' fOr },ome, industry and defense; including High Fidelity"Consoles;
Schoo!, Sound, Intercom and Public Address Sys tems.
~-'t'!'- .... -....
~
ge~
~_¥
,;ilt~G"J,
~"t(tl~''1''"
53
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
been found that the tape hiss on a "first
generation" duplicate is a little higher
than that of the "master" but not seriously so . Also, there is the possibility
that some differences of pitch will be evident to the trained ear. However, this is
usually not serious enough to bother
unless the tape machines differ markedly
in speed or the listener is "cm·sed" with
absolute pitch.
Sound-on-sound recording is also possible. The usual procedure for addition
of material to material already recorded
makes use of an extra p layhead in front
of the erase head. The original signals
are mixed with the material to be added
and the composite material is then re-
corded in the usual manner. With the
Viking deck the procedure is somewhat
different. The original material is recorded on the "wrong" side of the tape.
(The tape must be new or erased completely beforehand!) It is then p layed
back and mixed with the additional material : the composite material is then
recorded on the regular side of the tape
in the usual manner. This arrangement
has the advantage that the original recording is not destroyed. With a little
ingenuity the process can be repeated
several times.
From time to time requests are received for single-track recordings of
material originally recorded in stereo.
Using a second tape deck the two signaIs
are played back, mixed, and then recorded on a single track. Usually some
trial and error is necessary before good
balance is obtained but nothing is lost
except time.
A more ·prosaic use for this amplifier
might be mentioned. At one time or another most audio fans are called upon to
set up sound reinforcing systems for
special events. This recording amplifier
can be used as the preamplifier and mixer
for such a system . Simultaneous r ecording can be carried on as required. So far,
there have been no requests fol' ste'reo
sound reinforcement but it i.· obviously
possible with this unit!
Conclusion
" It's not Hi-Fi if it doesn't have Tung-Sol Tubes"
What we're driving at is the simple fact that Tung-Sol Audio
Tubes are preferred by makers
of the finest Hi-Pi equ ipment.
TUNG-SOL ELECTRIC INC.
Newark 4, N. J.
@TUNG-SOr
AUDIO TUBES
54
Development of the r ecording-playback amplifier required many weeks.
Many circuit anangements were tried
ou t "on paper" and "in the flesh" before
the final version was completed. Perhaps
a few words of caution are in order.
No one should attempt the construction
of a unit of this kind unless he is thoroughly conversant with good audio techniques. Good wiring practice must be
followed. Ground loops must be scrupulously avoided if hum is to be minimized.
Some experimenting with chassis grounding points may be necessary for the lowest possible noise level. After construction is completed proper adjustment
requires the intelligent use of a widerange audio-frequency generator, oscilloscope, sensitive a.c. vacuum tube voltmeter, and various other instruments.
The system which has been described
has been used for several months and
has given excellent results once sufficient
experience was gained for its proper
operation. The writer happens to live
in an area served by stereophonic broadcasts using AM and FM. Many of these
programs have been recorded and within
the limitations imposed by AM on one
channel the results have been highly
satisfactory. Live stereo recordings of
chamber music and choral groups have
been uniformly good once the problems
of proper microphone placement were
solved. Experience is the best guide here
and no absolute rules can be given. Tw()
identical car dioid microphones have
given the best results in all cases.
Earlier reference was made to t\le
"hole-in-the-middle" effect. This is hard
to desc'i"ibe in· words but a recent visitor
put it this way: "It sounds as though
you hear two point som·ces instead of
one." Most available recorded ster eo
tapes a void this effect provided that the
two loudspeakers are p laced flat against
the wall away from the corners of the
listening area. The wr iter prefers corner
horns for their low-frequency efficiency
but he often experiences the "hole-in-themiddle" effect when these horns are used
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
•
SEPTEMBER, 1958
f01' stereo reproduction. It can be effecti~ely eliminated by using a third, or
middle, channel whose signal material is
derived from both outside channels. This
was the main r eason for inclusion':, of
the hybrid channel in the system "described. It requires a third amplifier
a nd speaker but the results ar e worth
the price. It should be mentioned that
the two outside channels are combined
without the use or' a resistance mixer.
Electronic mixing is used to avoid crosstalk between channels. There is some unavoidable cross-talk between the two
heads mounted in-line and there is no
need to increase it.
The only valid obj ection to this system is its size and weight. It should be
possible to r educe both by the use of
transistors to replace some or all of the
many tubes now employed. Work is now
progressing along this line but that is
a nother st01'Y.
P ARTS LI ST
Resistors
1 megohm, lh watt
2200 ohms, 112 watt
2200 ohms, 1 watt
0,22 megohms, 1 watt
1,000 ohms, 112 watt
0.56 megohms, lh watt
3300 ohms, 1 watt
47,000 ohms, 1 watt
O,l·megohm potenti'
ometer, audio taper
0.1 megohms, 1 watt
0.62 megohms, lh watt
1000 ohms, 1 watt
10,000 ohms, 1 watt
0.27 megohms, 1 watt
0.82 megohms, 1 watt
0.25 megohm potenti omete r, a udio t aper
NEW
SPEAKER
SYSTEMS
Some speakers and
speaker systems provide
clean, sha rp transients
at low and low-low frequencies. Others are
very linear in response
at low and low-low· f4"e'quencies. Ory/y the new
Stromberg-Carlson mu/speaker systems
yau both.
end frequency
response extends at
least an octave below
that heretofore possible.
The range of our MSS·
492 system is 16-22,000
cps; the range of our
MSS-49 I system is 2218,000 cps.
Speaker system resonance is lower than the
unboffled free air cane
resonanc::e of the woofers. Exceptional transient response, linear
ql.!ality and extraordinary low f requency response are directly reo
lated to a carefully integrated design between
our . woofers and our
quarter wavelength
Acoustical Lllbyrinthil!>
baffling system. Threeway crossover networks
are included.
MSS-491 SPEAKER SYSTEM
15" Soft Skive r Woofe r, 8 "
mid-range, Induct ion Tweete r.
Available in mahogany, wal-
nut or limed oa k. 321/.. " high,
38%" wide, 21" deep. PRICE,
Mahogany, $379. 95 *; Walnul,
$389 .95 *; limed oak, $389.95 '
(Audiophile Nel) .
MSS-461 SPEAKER SYSTEM
8" mid-range, 2% " tweeter.
Available in mahogany, oak or
walnut. 24% " high, 19" wide,
10" deep. PRICE, Mahogany,
$69 .95'; Walnul, oak, $74.95 '
(Audiophile Nel) .
0.27 megohms, lh watt
22,000 ohms, 1 watt
2 megohms, lh watt
0.1 megohms, lh watt
0.47 megohms, lh watt
1800 ohms, 1 watt
0.22 megohms, lh watt
4.7 megohms, lh watt
50,000-ohm wirewound potentiometer, linear t aper
33,000 ohms, 1 watt
27,000 ohms, 1 watt
62,000 ohms, 1 watt
100 ohms, 1 watt
100-ohm wire''wound
potent iometer, lin·
ear taper
10-ohm, 25-watt wirewound, adjustable
1250 ohms, 20 watts
RU B
MSS-492 SPEAKER SYSTEM
12 " Soft Skive r Woofe r, 8 "
mid-rang e , two 2 1/2 " Tweete rs .
Availabl e in che rry or walnut .
32112 " high , 33 3/ .. " wid e, 16 3/ .. "
dee p. PRICE, $249. 95 ' (Aud iophil e Ne l) .
. .
.
~
RT-476 2 3/. " Tweeter•
$9 }15* (Audiophile Nell
.
For Full Dolo On An y And
All Ite ms , See Your Deal er
O r Write Us Dire ct.
• All prices a re Zone I.
" There is nothing finer than a Stromberg·Car/son"
STROMBERG-CARLSON
Capacitors
oI
G" G" Gw G"
50-/.I.f , 6-volt electrolytic
0.05-/.I.f, 6-volt paper
V I S I 0. N
0 F
G £ N ER A LOY N " ,......M..JJ: S
14 18C N. Goodman St reet
•
CO R P O R A '!..L2...~
Rochester 3, N. Y.
Electronic and communication products lor home, industry ' ontJ d efe nse ; including High Fidelity Consoles;
Schoot Sound, In tercom and Public Address Sydems.
AUDIO
•
55 :
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
T)Vteeted
SEPARATE AND BALANCED
O.l-l1f, 600 volts p aper
40 :~ , 450-volt electrolytic
C", C,"
c,'
c,,'
c,,'
C~O,
c,,'
~~~~
25-volt electro-
lytic
CIS,
c,,'
C' .I' C70 ,
C'" C"
STEREO
50-~[ f,
c'" c"
C '" C,.\I C.I " C"
20-l1f, 450-volt electrolytic
8-l1f, 450-'-olt electrolyti c
25-.i-tf, 25-volt electrolytic
100-I1i-tf, mica
O.4-~f,
600-volt pap er
0.05-l1f, 600-volt paper
0.006-f.lf , mica
0.0005 -l1f, m1ca
O.Ol-l1f, mica
6000-1111£, mica
0.25-~f, 600-volt pap er
1000-I1).1.f, mica
2400- l1f, 20-"olt electroly ti c
Miscellaneous
You can use Frazier-Engineered
High Fidelity Speaker Systems
for true separate -channel
st ereo or for monaural
reproduction-and get all
the musical enjoyment you want.
Remember, too-it is not
the size of the drivers,
but the way they are coupled
to an acoustically-adequate
enclosure that gives you the
range, the balance and the
realism you want, with minimu m
distortion, without coloration,
overdrive or hangover.
Your listening is not complete
until you hea r the Frazier.
(liodes
2-ampere f uses
Closed-circuit j ack s
Open-cir cuit jacks
HIGH FIDELlTVfoz,;R STEREDRAMA
Utilizes two Frazier Mark II high fidelity speaker systems with 3D-degree separation, in smart contemporary
enclosure. The 30-degree separation and projection assure excellent stereo effect at distances of five feet to as
much as sixty feet. Balanced reproduction from 30 to
17,000 cps. High efficiency p ermits use of any 12-watt
stenio amplifier. When used as a monaural system, " bigness" is obtained way beyond the cost. Size: 54" x 43 Y2"
x 32". Finished in Fruitwood Mahogany, Blonde Korina,
Walnut, Dark Mahogany, or Ebony.
Net, $295
STEREORAMA JR. D esigned like the Stereorama, but
utilizes two Frazier F -8-3X Black Box speaker systems.
40 to 15,000 cps. Size: 45 % " x 30" x 18".
N et, $195
WIDE-RANGE
foZ';R
4-30 mll a djustable
coils
I5-H., 65-rna chokes
DPST switches
SPST switches
2-ampere selenium
r ectifier, full-wave
bridge
Micr ophone-to-gri d
transform er s
Bias oscillator coil
(Viking D501 or
( eq uivalent)
6.3-volt filament t ransformers
350-0-350 volts at 70
rna, 5 volts at 2
amps, 6.3 volts at 2
amps.
12AX7
L" L j
S" S" S,
S." S" S,
SE
T.I , T ,
T,
MARK
n
Exceptionally wide range high fid elity speaker system.
Employs Frazier modified Helmholtz-type enclosure
with specially-designed 8-incll woofer and compressiontype tweeter. Smooth response 30 to 17,000 cps. Use as
is or in walls, closets, or other locations.
Size: 22 Y2 " x 26" x 16".
N et, $99.50
Available also in Capri cabinet. Net, $137.50
I2AU7
5879
6E5
VRI50
5V4
1£
POPUlARfoz,;R DEL MAR
Remarkable high-fidelity performance in custom-crafted
cabinet at low cost. Uses highly efficient Frazier modified Helmholtz direct radiator type speaker system,
with specially-designed 8-inch driver and cone-type
tweeter (as in Frazier F-8-3X Black Box) . Gives clean
r eproduction from 40 to 15,000 cps. Size: 23]1" x 23 >i" x
11 ]1". Finishes as Stereorama above.
Net, $79.50
25 years in electro-acoustics
Many Other Hi-Fi Models
Available at Frazier Dealers
to Meet Your Sp ace and
Budg et Requirements
Write to Dept. A for
Informative Bulletins
International Electronics Corporation
2649 BRENNER DRIVE, DALLAS 20, TEXAS
STEREO
(I?'om page 28 )
tem is a field type sound reproducing
system in which two or more microphones, used to pick up the original
sound, are each coupled to a corresponding number of independent transducing
channels which in turn are each coupled
to a corresponding number of loudsp eakers arranged ,in substantial geo, "
metrical correspo1Jaence
to that of the
microphones, as in Fig . 4.
AUDIO
56
www.americanradiohistory.com
AmericanRadioHistory.Com
•
SEPTEMBER, 1958
Description of Systems
Following the definitions! of monaural, binaural, monophonic, and stereophonic sound the next consideration will
be a description of some of the characteristics of the four systems.
To achieve realism in a sound reproducing system, foul' fundamental conditions must be satisfied, as follows:
1. The frequency range must be such
as to include without frequency discrimination all of the audible components of the various sounds to be reproduced.
2. The volume range must be such as
to permit noiseless and distortionless
reproduction of the entire range of intensity associated with the sounds.
3. The reverberation characteristics of
the original sound should be approximated in the reproduced sound.
4. The spatial sound pattern of the
original sonnd should be preserved in
the reproduced sound.
A diagram of a monaural sound reproducing system is shown in Fig. l.
The most common example of a monaural sound reproducing system is the
telephone in which there is, in general,
a single source of sound, one microphone, a transducer, and one telephone
receiver coupled to one ear of the listener. In most local applications, the
carbon microphone is coupled directly
to the telephone receiver. In long distance telephony vacuum tube and transistor amplifiers may be used between
the microphone and loudspeaker. For
other more limited applications, as for
example, monitoring purposes, the transducer may be a r adio transmitter and
receiver, a television sound transmitter
and r eceiver, a disc phonograph recorder
and reproducer, a sound motion picture
recorder and a r eproducer andlor a
magnetic tape recorder and reproducer.
In some applications, there may be more
than one sound source. One or more microphones may be used. In some applications two telephone receivers may be
1 The definitions of the terms monaural,
binaural, monophonic, and stereophonic,
agree substantially with those of modern
dictionaries. In addition, t he terms binaural
and stereophonic as defined in this paper
have been standardized. As a result, the incorrect usage of binaural to designate a
stereophonic system is disappearing. Monaural is still incorrectly used to designate
a single-channel field-type sound reproducing system. Monophonic is a relatively new
term, which has been introduced to supply
a void in terms to describe the four fundamental sound systems. Monophonic and
ster eophonic are harmonious and congruent
terms which complement each other and
have a common relationship in describing
field-type sound systems. Monaural and
binaural are also harmonious and congruent terms which complement each other
and have a common rela.tionship in describing closed-circuit sound systems.
AUDIO
•
PR-488 AUTOSPEED
CHANGER :
. Pe rformance motches or exceed s the fineft. It is the onl y
changer that cannot damoge
record surfaces.
PR- 499 AUDIOPHILE
TURNTABLE :
SPECIFICATIONS :
This is the first turntable with
double-acting dual suspension, combined with elastic
belt drive and continuously
variable torque drive .
Th ese specificat ions shown below a re those of a Stromb erg -
Corlson turntable mo·chined to
th e worst tolerances poss ibl e
unde r manufacturing conditions .
W e wi ll guarantee all delivered
turn tabl es to exceed these specifications .
AUTOSPEED, Automatically
changes speeds and intermi xes
records for 33 and 45 RPM with
stylUS at microgroove position ,
without rega rd to sequence.
Operates at 78 RPM automati·
call y with sty lu s in 78 position.
BALANCED
ARM,
Th e
stylus
pressure is variable to less than
one grom , less thon an y other
changer. CHANGE CYCLE STOP ,
Five-second change cycle .
ACOUSTICALL Y ISOLATED
TONE ARM, trouble·fre e-th e
tone arm con be handled at
any time without dam ag e or
dislocation. IDLER WHEEL DISENGAGE. FOU R SPEED AUTO·
MATIC AN D MANUAL OPERA·
TlON . MUTING SWITCH AN D
FOUR·PO LE MOTOR. DIMEN ·
SIONS: 13'12" wide, 12 " deep,
3" below an d 5 " above mounting board. MODEl PR·488 DS ,
GE VRII Diamond/Sapphire
Ca rtridge,
$84 .95". MODEl
PR·488 SS, GE VRII Dual Sap-
phire Cartridge, $74.95. (Pri ces
Audiophile Net.)
SPECIFICATIONS :
NOISE LEVEl, 55 db down .
WOW, Less than 0.25% peak
(0.18% RMS) . FLUTTER , 0.1%
peak (0 .01 % RMS) . SPEEDS,
Continuously variable from 14
to 80 RPM , guarant eed to be
comp lete ly cons.ta nt at any s.etting . STROBOSCOPIC WINDOW
PILOT LIGHT , Vi sual gu ide to
a cc urate speed. DOUBLE SUSPENSION SYSTEM, Turntable
and arm are suspe nd ed above
mounting plate, moto r ben eath
fo r comple te iso latio n. HUM
FI ElD : Motor is isolated from
ma g netic cartridge hum field .
BELT DRI VE, Ela stic be lt drive
prevents
rumbl e
transmi ssi on .
MOTOR, Four ·p ole . DRIVE ,
Cone dri ve on idle r wheel, separa tes comple tely in " off" positi on . Dri ving press ure: from
torque of drive cone . 45 RPM
CUTOUT: No ma nipulation ne cessa ry for 45 RPM re cords.
DECK: Provide d wi th legs for
operatio n without bos e . FINISH: Morocco red, aluminum
trim . PRICE , $99.95' (Audio·
phile Net) .
SR- 440 AM-FM TUNER:
TUNING RANGE , FM·88 t o 108
MC; AM-540 to 1600 kc. IF
BAND WI DTH , FM·200 kc . AM·
15 kc, broad posi tion . 8kc
sh arp position.
FREQUENCY
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used transmitting the same program to
each of the ears of the listener. The
monaural sound reproducing system is
of the closed-cil:cuit type in which the
oar of the listener is transferred to a
microphone location by means of the
microphone, transducer, and telephone
receiver combination. The acoustics of a
single room are involved in the reproduction of the sound, namely, the studio
in which the microphone is located. The
monaural sound reproducing system may
be constructed so as to satisfy conditions 1, 2, and 3 on realism of sound reproduction. It cannot, under any conditions, satisfy condition 4.
A diagram of a binaural sound repl'Oducing system is shown in Fig. 2. There
is no widespread use of the binaural
sound reproducing system. The use is
limited to specific applications. The binaural sound repr oducing system consists
of two separate channels. Each channel
consists of a microphone, transducer,
and telephone receiver. The microphones
are mounted in a du=y simulating the
human head in shape and dimensions
and at the locations corresponding to the
ears of the human head. The transducer
may be an amplifier, a radio transmitter
and receiver, a phonograph recorder and
reproducer, a motion picture recorder
and reproducer, or a magnetic tape recorder and reproducer. The binaural
sound reproducing system is of the
closed-circuit type. The listener is transferred to the location of the dummy by
means of a two-channel sound reproducing system. The binaural sound reproducing system may be constructed so
as to satisfy all four conditions on r ealism of sound reproduction.
A diagram of a monophonic sound re'producing system is shown in Fig. 3. It
is the most widely employed of all sound
reproducing systems. Examples are the
disc phonograph, radio, sound motion
picture, television, magnetic tape reproducer and sound systems. The monophonic sound reproducing system is of
the field type, in which the sound is
picked up by a microphone and reproduced by means of a loudspeaker into a
field. The sOlmd at the microphone is
reproduced at the loudspeaker, The
transducer may be an amplifier, radio
transmitter and receiver, a phonograph
recorder and reproducer, a sound motion picture recorder and reproducer, a
television transmitter and receiver, a
magnetic tape recorder and reproducer.
The monophonic sound reproducer may
be constructed to satisfy conditions 1,
2 and 3 011 r ealism of sound reproduction. It cann'ot under any conditions
satisfy condition 4.
A diagram of a stereophonic sound
reproducing system is shown in Fig. 4.
The stereophonic sound reproducing system is of the field type, in which the
AUDIO
58
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SEPTEMBER, 1958
sound is picked up by two or more micr ophones which are coupled to a corresponding number of independent
transducing channels which in turn are
coupled to corresponding number of
loudspeakers arranged in substantial
geometrical correspondence to that of
the microphones. The transducer may be
an amplifier, radio transmitter and receiver, a phonograph r ecor der and reproducer, a sound motion p icture recor der and reproducer , a television
transmitter and receiver, or a magnetic
tape recorder and r eproducer. Two channels are used in the disc phonograph
and radio. Two and three channels are
used in the magnetic tap e reproducer.
Two, three and more channels are used
in motion picture reproducers. The
stereophonic sound r eproducer may be
constructed to satisfy conditions 1, 2
and 3 on realism of sound reproduction.
It can be constructed t o provide auditory perspective of the r epr oduced sound
and in this sense the stereophonic sound
repr oducer satisfies condition 4 on realism of sound reproduction. Stereophonic sound is being r apidly commercialized. The first wide scale use was
in sound motion pictures. This was followed by the magnetic tape reproducer.
The stereophonic disc phonograph is being commercialized this year. Experiments are now being conducted in the
transmission and reproduction of stereophonic sound by means of a radio system. In one arrangement, the two channels are transmitted on two separate
ra dio links, one by a frequency modulation system and the ' other by an amplitude modulation system. I n another arrangement, the two channels are transmitted and reproduced by means of a
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Summary
The four fundamental types of sound
reproducing systems- namely, monaural,
binaural, monophonic, and stereophonic
- have been defined and described in
this paper. The terms monaural and
binaural are used to designate closed
circuit so und reproducing systems. The
terms monophonic and stereophonic are
terms used to designate field-type sound
reproducing systems. Monaural and binaural (01' monophonic and stereophonic)
are mutually harmonious and congruent
t(;rms which complement each other in
describing closed-circuit type (01' field
type) sound reproducing systems. The
definitions as presented in this paper
agree substantially with modern dictionaries. The terms binaural and stereophonic have been standardized. I n view
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all foul' terms, monaural, binaural,
monophonic, and stereophonic are standardized.
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EDWARD TATNALL
1. KEYBOARDS OF THE PAST
Cimarosa : Sonat,a s (complete). R. Veyron Lacroi x, harps .
Westminster XWN 18698
'l' his on ce·fam ou s Italian of the time of Mozar t and H ayd n is kn own ordina rily f or his
opera HI! Matrim onio segreto" (Secret Marriage) - and not '- er y well know n , at t hat; but
even Mozart t hought well of h im . T h ese shor t
li ttle one-movemen t sonata s fo r harpsich or d
( they coul d w ell h ave been pi ano wo rks, bu t
suit t h e ha r psichord t o perfecti on ) we re t h e
product of an interlude in a n ot b erwi se bu sy
car eer, t h anl, s to the political upheavals of the
French Revo lu t ion, T hey a r e n ominally in t h e
style of Scarlatt i an d m ay"\ vell r emind li stener s of t he ma n y Scarlatti h a rpsichor d son a t as,
bu t t h e date is con siderably later and t h er e
a r e man y t ra its of t h e Mozar t-Hay dn peri od , to
give these a new sort of ha rps ichord piqu an cy .
A valu able a ddit ion t o t h e r ecord ed re per tO t'Y , a s t h e old phrase goes, and a pleasin g
complement t o better kn own h a rps ichord mu sic. M. " ey ron -L acr oix's som ewhat w iry harpsichord is expressiv ely played.
Dussek : Piano Sonatas Op. 61; Op. 45,
# 1; Op. 20 1 # 2; Sonata for Piano Fou r
Hands Op. 32. He ida Herma n ns, Ruth
Stone ridg e, pfs.
Society for Forgotten Music SFM 1002
T his "f o rgotte n m u sic" is a n oth er w ell
wo r thwh il e a ddition to availa l)le pia no recording. Dn ssek was a Czech (Boh emia). somewh at
younger than Mozar t , who composed migh till'
at t he end of tile eig h teenth cen rury, at the
tur n towards Romanticism. His last so nata,
Opus 61, of t he t ime of early Beethoy en , is
cla imed t o be extr aordin a rily Rom a n t ic in
cast a nd perh aps a fo r erunner of mu ch to come.
I found th e oth er s, in a n earlier and m or e Mozar t-like s ty le, just us inter estin g. Altogether
a n impor t an t " seco nd-lin e" composer , obviously un able a nd skillful writer. P ia nis ts, as
w ell as record li stener s, will enjoy th e goo d
playing h ere. ('l'h e company is a di vision of
Con temp ora r y Records, Los Angeles.)
Ha ydn : Piano Sonatas # 52, # 34, # 43 .
Nad ia Reisenbe rg . (vol. 2).
Westminster XWN 18358
This music, except f or the l as t big Son ata in
E Fla t , ( # 52) , is actua lly of earlier date t h an
t he Cimarosa above-but it seem s later. Th e
music is clearly piano-s tyle, t h e sonatas a r e
multi-m ovem en t ins tead of the short one-movement ty pe.
H aydn 's piano sonatas have had a small and
devo ted following, m a inly a mon g amateur pianists who r ead endlessly and not ver y w ell
t hrough t h e numeron s published volumes familiar to most pia nists. Th ey a r e quite unlike
t hose of Mozart, th ese s ona tas, both mo re a dvanced, more like B eethoven, ye t in a w ay of
an earlier time, H aydn being considera bly
older than Mozart; Nadia Reisenber g i s a go od
* 780 Greenwich St., N ew York
14, N . Y .
CANBY '~
pianist fo r t hem. Sh e makes them soun d a s bi g
a s they actua lly a r e (most pia nis ts m ake th em
t inkle like fr agile minia tnr es) , yet she does not
roman t icize t hem.
They a ren't demons trative, t hey are seldom
sh owy ; but after a few play ings t hey are likely
to s tick in yo ur m emor y. In tru e H aydn style,
most of t his mu sic is fa r more profoun d th an
it outwa r dly seems; Haydn was a peculia rly
ret icen t soul. In the big E Flat son ata especially (dating f rom af ter his last symphonies)
t here a re extrao rdina r y near-Roman t ic ex pressions, r emar kable modula tion s, into st ra nge
keys, a r eally powerf ul expression , all in fa irly
gentle outwar d t erms.
This is one of a continuing series. If you
en joy it, t h er e'll be more coming.
t hose days ; thu s, as pla yed her e on a s plendid
old French organ built fif t y year s befo re h is
t im e, t h e mu sic is a bout a s clo se to the actual
so und of Couperin' s day as w e sh aIl e,'er get
in an y a r t is tic r econ struction . L ovely, especially t he r eedy trumpet s t ops a nd t he C"omorn e (Krumhorn ). cont rasted again st the
soft-toned Tier ce.
Marcha l is the great bli nd o rga n ist of
Fra nce, r ecently h eard in several or gan recor ds made at M.I.T. in Cambridge, Mass. A
r ather deliberate playe r who phrases his mu sic
car efully, h e is an excellent player fo r t h is
delicat e m usic.
Th e Titelouze piece is an ea rlier w ork, varia tion s built upon a Latin h ymn . It takes u p
t h e last piece of Side 2- th e r est is Cou perin .
Handel: Keyboard Music i Vols. I, II
(Suites # 3, # 13, # 11 ; Suites # 14, #1 5 ,
# 8). Paul Wolfe, harpsichord .
Exp. Anonymes EA 0032, EA 0033
Le Roux: Pieces de Clavessin-1705 . Al be rt Fuller, harpsichord.
Overtone 15
A millio n pianist s h ave played various movemen ts f rom th ese H andel suites as pa r t of th eir
heg inni llg l(ey boa l'd t r a inin g; not on e in a t h ou sand of us ever hear s t he familia r li ttle pieces
in th ei r origina l context and on t he origin ally
in t end ed in strumen t ! They a re ever so clearl y
improved by the h a rpSichord playing.
Pa ul Wolfe is a gifted and fluent young pe rfo rm er , stable as a r ock and accu ra te as to th e
impli ed l'hythms and orn am en tation th at a
harpsichordist mu st add t o the literal w ritt en
notes, imaginative in his registr ation fo r harps icllOrd tone color. Only a somewhat metr onomic an d too-mech anical tempo (as I h ea r it,
an yhow) cuts down a bit on t he expressiveness of t hese brillia n t works.
The harpSicho rd is a large one with a gorgeou sly H andeli a n sound t o it and t he r ecording makes it seem even larger . K eep t he yolum e
down, a s you listen, if you wa nt a faith ful
harps ich ord soun d.
Couperin: Messe a L'Usage des Couvents.
Titelouze: Four Versets o n /lAve Ma ris
Ste lla ." Andre Marchal, o rgan a t La
Fl e che, France.
Westm inster XWN 18674
Ah- if only th ese older works h a d s im ple,
ea sy t itles, like " Dreaming of You" or " T ea
fo r T wo" ! The lon g spiels in s trange languages
often a re mu ch h ard er t o under st and t h an t he
mu sic itself.
This is a Mass, n ot a mess, t o begin w it h .
It's no m ess at all, but a series of shor t organ
pieces g rou ped a round t he fiv e sect ion s of
t he Cath olic Mass and in t ended f or use in
conven ts and mon ast eries of t he la te Sixt een
Hundreds in gloriou s France under t he g r eat
Loui s X I V. . T he composer wa s only 21, bu t
alr eady was a top figure in t he King' s mu sic.
Th ese litt le " couplets, " som etimes eight or
nine to a section, must have been played as
brief interl ud es or " background music" to th e
actual Mass. Th ey a re as sweet and wholesome
as a glass of light French wine, bea utifully
tinted in contrasting individu al tone colors.
The most inter est ing aspect of the mu sic is
tha t young Couperin actually specified the
pa rticular s tops he intended, a rare thing in
60
- And h er e, from the same period a s t h e
Couperin, is a set of h ar psichord suites in t he
ela borately orn a men t ed French m a nner of
Cou pe rin 's own keyboard music- a style th at
h as come back into i ts own on the h a r psich or d,
wh er e on t h e piano it w a s virtually meaningless a nd quite un playable. French mu sic of t he
L ouis XIV a nd Louis XV period is staging a
mon umental comeback these days, a n d a "new "
composer of t he period, n am e unknown, is n o
l on ger surprising.
L e Roux was an excelleut mu sica l wor kman
in t he br illian t circle of Fren ch mus ic a n d art
t hat existed t hen . Few of u s could t ell that
these fl uen t wo rks wer e by an "u n known "
composer. The Sui tes, as was cll stoma r y t hen ,
a r e loose collections of short pieces in a com·
mon key, each with a da n ce-f orm title or a fa nciful n ame-one of th ese is called " The P iece
w it hou t a Title."
You didn 't h ave t o pla y th em all in t he order given , then, a nd you don't n eed to n ow. An
excellent record f or sampling, a n L P band or
so at a tim e-or f or nicely sophisticat ed backg round dinn er music. (But don't t eIl t he per f ormer I said so.)
Buxtehude: Complete Org,a n Works, vol.
6: Toccata in D Mi., 2 Chorale Fantasias,
3 Chorale Variations. Aif linder, orga n
a t Ski:inninge, Sweden .
Westminste r XW N 18689
This co nt inues the intermittent Buxtehude
orga n series , on a fine oIel Swedish organ-t h e
s ame on which t he Wes tmin ster Bach series is
issued, wi th Carl Weinrich.
Other r eports may have been "glow ing"I'm n ot tha t enthusiastic, though Bux t ehude,
t h e jolly North German ( Swedo-Da nish ) pred·
ecessor of Bach , i s one of m y own f avorite organ composer s. My slight r eser vation s a re on
t w o coun ts; first, Alf Linder plays Buxtehude.
it seem to m e, with a slig htly heavy h a nd
(speaking fi g ura tively ) and less h umo r , in a ppropria t e places, than he m ight. Rather se rious·
minded, t hough excellent as a pla yer . Second,
there is t he " hi-fi" Westminster-style r ecording, which somehow disembodies t he organ ,
bringing practicaIly every pipe close t o you
(via multiple m iking, as far a s I kn ow) . It's
no serious objection , but I still like a more dis·
AUDIO
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SEPTEMBER, 1958
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tant, perspective-giving pickup for t bis type of
mus ic.
Matter of taste, on both of these poin ts, and
you may find you feel quite otherwise.
Bach: Organ Works, vol. 4. (Fantasia in
C, Fugue in C Mi., Preis and Fugues in F
Mi., D Mi., G Mi., Trio in G.) Anton
Heiller, organ.
Epic LC 3462
The mere fact that in this recording the
particular instrument being u sed is no t specified is a clu e to its natur e, a sincere, dignified,
somewhat noble and occasionally monotonous
playing of much B ach in a style that is already
rather old-fashioned, out of the time of
Schwei tzer. It will stress for most listen er s
the n oble monumentality of Bach; those who
are not well versed in Bach's mu sic will find
the sou nd and the playing unspectacular. Bach
lovers will apprecia te the good musicianship
underlying this somewhat stolid Viennese
approach .
Oddly, Heiller is a young organ ist, under
fort y. Hi s playing is t h at of a n older generation of Bach organists, far r emoved from the
now popu lar "Baroque" or Classic approach.
2. CLASSICAL WINGDINGS
Copland : Billy the Kid (1938); Rodeo
(1942). Morton Gould & His Orche stra.
RCA Victor LM 2195
A good record , this one! H ere are the two
Copland ballets that first launched t he vogue
for Western material in ballet form- they've
s ince been followed by innum era ble examples
in ballet, in films, mu s ical comedies, TV shows.
Just as it took a German, Handel, t o show t he
British h ow to w rite British oratorio, so it
t ook th e boy fro m Brooklyn, no cowboy himself. to write t he first effective Western music
fo r OU I' own ballet stage.
'rhe th ing about Copland is t hat hi s stull' is
stri ctly high-level -yet it is strictly e'n tertaining and strictly Western, without comp romise. No highbrow effects h ere! Ther e's a barroom piano with th umbtacks in it s hammer s
to make it tinn y enough, there's a low-down
hoe-down and an old-style square dan ce-th e
titles of the parts run from Buckaroo Holiday
to Co rra l Nocturne. But even so, the music is
on a sy mphonic plane and up to anybody's
s tandards fo r "classical." Copland s howed
how you could be classical and Western too
a nd lI e' s justly a dmired for it by all concerned.
(Credit , too, goes to h is dan ce coll eagues, such
as, h er e, Lincoln Kerste in , Agnes de Mille,
E ugene Loring.)
It takes cr aftsmen like Aaron Coplan d to
keep music aliye an d healthy-eyen if he isn 't
exactly a Mozart from New York. Th ere are
many such, and they a re vital to musical developmen t. I'm su re t hat in engineering and
oth er sciences the same sort of men are
equally adm ired-for the same superior sk ill,
tenaCity, im agin ation , inability to do a poor
job no matter what. Copland is not t h e great
Ameri can musical genius, bu t he is surely onc
of the best workers in American music ever to
have pu t hi s ser vices at our disposal. You can
h ear it, in hi s work, and you' ll both respect
and enjoy it.
Mo r ton Gould was an excellent choi ce for
these works-his playings are as fine as they
come. H is own orchestra is always crackerjack and though his own composing style is
generally far f r om Copland's, he obv iously
apprecia tes t he splendid n ew territories that
were staked out in these ballets and his interpretation does them proud , with fu ll understanding. You'll get the feeling h e wi s hed he' d
written them himself.
The Moldau (The Mold,au, Inv. to the
Dancey Meph is to- ,W altz,. Minuet. of the '
Will 0' the Wisps, Dance of the Symphs,
Rakoczy March .) Philadelphia Orch., Ormandy.
Columbia ML 5261
Columbia' s du r able and wid e-selling list of
old favor ites by the Philadelphia is always
hard to review-there really is n't much to
say, though t hese r ecords probably account fo,·
a good hunk of th e total popular claSSics market sa les.
They just go on and on, they get bett er and
better technically, and Ormandy proves always
to be a superb conductor of war horses, who
somehow makes them sound on r ecords as
though t hey hadn't been played fo r several
mon th s. FreSh, musical, well-ta ilored. expertly
to ned, th e still' doesn't sound a bit h ackneyed.
Don ' t know how they do it.
Tchaikowsky: Piano Conce rto # 1. Van
Cliburn; Anon . orch ., Kondrashin .
RCA Victor LM 2252
Biggest surprise of t he year- at least to me:
t his t urns ou t to be a really " ery nice reco rded
performance of the familiar Co ncerto: with
much unexpected wa rmth a nd sincer ity, a
" n ew appr oach " feeling, that comes both from
t he earnest young pianist and the unaccusto med leadership of t h e visiting Russian conductor. Th e sound is good, too, though RCA
really h a d to rush this through to capitalize
on the great to-do over "Van," before it should
show signs of defl ation. Heartil y r ecomm en ded,
anonymous orch. or no.
Lev·a nt's Favorites. Oscar Levant, piano .
Columbia CL 1134
Oscar Levant is making a s pecies of comebaCk, I gather. I didn't know he had go ne away
-guess I d ieln 't notice. Anyhow, he's t he same
old Oscar h ere, the bad , naugh ty, brilliant boy
of th e old " In fo rm ation Please" (before t he
billion-dollar TV quizzes ) , the witty, erratic
piani st who a lways did anel st ill does seem to
play like an extremely gifted a ma teur.
Oscar goes in for Spa nish a nd FrenchRitual Fire Dance, Malagu ena, Cla ire de Lun e,
L e Cathedra le E nglou tie, the Alben iz Tango,
and even an odd li ttle in t ru sion by the moelern
Poulenc, ve ry ni ce. The playing is no t polished,
not r eally professional, fu ll of blurs an d unevenn ess; but it would be silly to eleny that it
has t h e old Oasby Levant persuas iveness. You'll
enjoy it.
Granados: Goyescas; EI Pelele. Eduardo
d e l Puye o, piano.
RCA Victor LC 3444
Here's some really profession al Spanish piano playing, a whole suite of Granados pieces,
which will hit th e ear more or less as fam iliar
stuff I t hink, plus one extra number t h at goes
into t he same general category. All based on
sketches by t he Spa nish artist, GO,l'a. Fine
playing, I'd say.
Tchaikowsky: Swan Lake (excerpts). Royal
Opera House Orch ., Cove nt Garden ,
RCA Victor LM 2227
Morel.
Ah! Scrumptuous. A fin e, smoothly a rticu lated and very much alive playing of the
fa mili a r (mos tly) Tchaikowsky ballet mu s ic,
with a minimum of t h at soggy, repetitive feeling that sometimes emerges from t his sort of
mu sic wh en it is heard minu s its visible dance.
This goes righ t a long, the verve mak ing up for
th e Inissing, un seen stage.
Moussorgsky-Ravel : Pictu res at an Exhibition . Chicago Symphony, Re iner
RCA Victo r LM 2201
Oof, wh at a high-power ed " Pictures" we
have h ere ! Disciplin ed, ta ut , a dmira bly played,
steely -true to Ravel' s orch estration, bu t for my
ears it is a ll cold chrome a nel lacks t he sombre
magnificence (to use the best cliche I can pull
out) or the origina l Mousso rgsky mu sic. A lot
of people will like it bett er t hi s way, maybe.
Schumann: Piano Concerto in A Mino r_
Chopin: Piano Conce rto # 2. Maria Tipo;
Bamberg Symphony and Pro Musica
Vox PL 10.32 0
Orch ., Pe rl e a .
Two solid warhorses in a Vox bid fo r com pet itive buying, but the competition is ou ly h alf
there. Maria 'l.' ipo continu es to be a big la dy
artist, an impul sive, co mman ding young pianist, wh o does a rousing job with a lm os t any
concerto sh e picks, though h er s tyle may be a
bit on th e rough -and-ready side. But t he two
orchestras here, playing as though one (I
couldn ' t tell th em nor t heir recorded so und
apart) seem to h ave been earnestly incompetent on these two occasion s. Mine is not to reason why; I can only state that the orchestral
backing is notably underpowered, through it
62
t ri es hard. Nice piano sound, nice or ch estr a
too-as far as it goes.
3. EUROPE IN THE OLD DAYS
Haydn : Oboe Concerto in C.
Dvorak: Seren·a de in D Mino r, Op. 44.
Me mbe rs the Ha ll e Orchestra , Barbirolli .
Eve lyn Rothwell, oboe .
Mercury MG 5004 1
Haydn was both a prolific and, eventually,
a very famo us composer within his lifetim e.
So was almost everybody else proll fic in those
days-especially when it came to writing mu sic that could pay well if palm ed 011' under
Haydn's name. There is plenty of pseudoHaydn, an d a lot of it sounds very mu ch like
the real thing. Is this Oboe Concerto of thnt
sort? There seems to be a question.
As to little old me, I somehow doubt if it is
by the old man himself, even in his earli er
period , a round 1760, t h irty years before the
well known symphonies. Only the last movement has a Haydnish ring to it, and the whole
piece is not only of a more elaborate ou tward
style than most of Haydn-full of typica l
"busy" playing of the sort that he did not so
exten sively indulge in-but the tunes an d harmonies a r e relatively lax, quite good humoredly
lacking in a ny fo rceful sh ape or color. A ni ce
piece and a good one, but no t good enough fo l'
old man Haydn, I say. The oboe playing by
Mrs. Barblrolli- Evelyn Rothwell profe ssiona lly- is superb. She's a whiz. Husba nd John
does a somewhat over-tensionecl orchestr a l
pa rt, more vigorous t han the music itself.
The lovely D vorak Serenade, for winds wi th
a few lower strings added, is given a lumin ous
but strangely cool perform a n ce h ere. That's
one way to do it, but I've heard this same
music played with much more intensity and a
powerfully romantic mood- and I liked It.
Still, this is surely a legitimately mu sical approach, and Mercury's one-mike sound makes
th e whole thing glitter and glow. A beautiful
mike pickup.
(The Oboe Concerto sound is excellen t, too,
with a n unu sually natural and musical balance
between t he oboe a nd the orchestra.)
Vivaldi : Concerto in G Mi . for Flute, Oboe
and Bassoon (without orchestra). Haydn :
Wind Divertimento in B Flat. Moza rt:
Wind Cassation in E Flat. Paris Wind EnEpic LC 3461
sem bl e.
Boy oh bo y! France is famous fo r virtuoso
winel playing and that's what we have her e,
wi th a vengean ce. The player s t oss th e th ree
works 011' (w ith t h at peculiarly nasal, brilliant
F ren ch wind tone quality) like so many technical exercises-and that, I s us pect, is what
t hey amount to in t his company. The whol e
thing reminds me of an engineering conferen ce-on ly t hese men talk musical shop. T o
them, it wou ld seem, Mozart and Haydn , Viva ld i as well, were so many wind teclmiclans.
Two items of special in terest. even ~o. nre
the Haydn , with the "Saint Anthony" t heme
used by Brahms in his ultra-familial' Variations on a Th eme by Haydn- this tune, note
fo r note-and, secondly, the interesting li ttle
Viva ldi Concer to for th r ee wind inst rum ents
all by themselves; they somehow ma nage qu ite
eas ily to give the impression of solos a ncl
"orchestra," in concerto grosso fashion. In geniou s. (Th is is a lready its second a ppea ra nce
on r ecords.)
Geminiani : Concerti Grossi, Op. 7 . I MuEpic LC 3467
sici .
Complementing its earlier Mozart anniversary series (hi s 200th birt h day, 1956) , EpicPhilips of Holland, to be precise-is running a
new one with a fancy Lat in name, Mon umen tn
Italicae Musicae, Monuments of Italia n Music,
under t he direction of a gen t with an Italian Dutch name, Vittorio Negri-Bryks. 'rh e r ecor dings by the famous I Musici (the lIiu slcian s)
in th is series seem to me to be s uperior to
those done earlier for Angel, a nd t he clifference is probably in the more lmowledgenb lc
histo rical direction, by the above-mention ed
Negri-Bryks.
Geminiani was one of the famous roving
Italians who brought the Italian mus ical influence in the eighteenth century to many
AUDIO
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•
SEPTEMBER, 1958
other countries; he spent much time in England and died, of all places, in Dublin_ His
sweet music is very much of the progressiye
sch ool of Bach's day, that, al ready, in Italian
term s, was lead ing onwards to the grace and
elegan ce of Mozart.
~'be wretched notes on this a lbum cover
don 't tell us about the interesting musical
sleigh t of hand in several of t h ese concerti ;
one of them is written in "three different
styles"-French, English and Italian (countries wh ere Signor Geminiani had made music
himself) , another is "the art of the fugue in
four r eal parts"-this in a day when the fugue
was blending handily into a symphonic orchestral style-and still another is written
in multiple voice-lines, 5, 6, 7, and 8 parts ,
a genial tour de force. You won ' t have to
fathom all of this to enjoy the flu ent writing,
t he rather feminine grace, of the Geminiani
music.
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Ca rtrid ge Wei ght .... 7.5 grams
Channel Iso/ation .. . 20 dac ibels
Stylus ............. Dua l jewe l ti ps,
O.7·mil microgroove and 3·mil 78
rpm .
Mountin g Dimensions . Sta ndard 7jru to 1/2
inch ce nters
Johann Stamitz: Orch. Trio Op. 1, # 2;
Oboe Concerto in C; Clarinet Concerto in
B Flat; Sinfonia
8 in D. Soloists, Munchener, Kammerorchester, Gorvin .
Archive (Decca) ARC 3092
a
Th e generally superb Archive series from
Deutche Grammoph on ' in Germany is far too
ex t ensive for the space we can occas ionally
give to it; I mllst fall back on occasion'a l samplings, to indicate the sort of things it covers.
For all those who have h ad a brief session
In music history and can remember mention
of "The Mannheim School" of pre-Mozart
composers-for an ybody who is curiou s as to
how Mozart got to be Mozart in style-thiS
pleasan t record is a revealing one. ~'here were
two younger Stamitzes from Mannheim, sons
of this one, who lived on after Mozart. But
they weren 't the real innovators. The father,
Johann , died in 1757- when Mozart was one
year old. It's the more r emarkable, then, that
in this, his music, so much that is basic to
the 'Mozart" sort of expression is al ready well
worked out. Stamitz died befo re h e was forty,
but he turned out vast amounts of music- 74
short symphoni es, for in stance, in the days
when th e symphony was just taking form as
a worthwhile device on its own.
Th e Oboe Con cer to is a somewh a t earlier
work, continuing inter estingly th e older plan
of the continuo accompanimen t, . harpsichord
harmonies to support tbe m\l~ i c . . (Haydn used
t he ' s'ame in his first couple of dozen symphOnies.) The Ciar inet Concerto, iatel', was
one of the very first big 'pieces for thnt instrumen t, long before Mozart's Clarinet Concerto, which set the instrum ent up in h igher
musical society for good.
Start with Sonotone 8T ceramic cartridge to
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Monteverdi-Selected Works. (Orig inally
reco rde d in 1937). Nad ia Boulanger, vocal and instr. ensemble Angel COLH 20
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This is a reissue (Great R ecordings of the
Century Series) of one of th e very first of t he
"old music" re>ivals, a 78 album that had an
immense effect on a whole generation of en·
thusiasts. J still r emember its impact, bac],
in the slim pre-war days when unusual ol el
music on records was practically unavailable.
The performance is, perhaps, more French
than Italian and somewhat out of date as of
present sta n dards, u sing a piano (played by
the great t eacher herself, Boulanger ) In s tead
of a harpsichord, but it was, and is, a power·
ful set of perfo rman ces, its a uthority still
enough to make any ea r li sten closely to th e
strange, wild music, voices and in struments
combined, of the great Monteverdi, a basic
mu sical pionee r and a geniu s to boot.
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Lassus: Missa VIII toni; 8 L-atin Motets.
(a ) Aa chener Domsingknaben , (b) Aache ne r Domchor, Rehmann.
Archive (Decca) ARC 3077
Here's one more Archive elisc that has int rigu ed my ear. Lussus, on e of the very biggest
and most universal composer s of th e late Six·
teenth century, is better known by choral
singers t han by most record l is t eners, since
hi s greatest output was in choral mu sic,
paralleling t bat of Palestrina but of a much
more varied scope, composed in four or five
rJifferent langnages, in eve ry cu rrent style of
th e Emo\)e of the day.
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•
ELMSFO RD, NEW YORK
•
63
SEPTEMBER, 1958
www.americanradiohistory.com
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•
•
a reassuring sign
'T hi s disc is, as far as I am concern ed, a
une-sider. and wo r t h the cost fo r that. Oddly,
there are two choirs h ere, the Ch ildr en 'S Choir
(Aachen Cathedral Singing Boys) and the
g rown -up choir of t he cathedral ; of the two,
t he youthful group is by far the best- it Sings
r ings a r ound the old folks! Its Lassus Mass
(Missa) is superbly alive and beautifully recorded ; you don ' t need to worry about the
L atin nor the fancy title-just listen straight
through and you'll know what Lassus had
to say.
'.rhe sho r t Motets s ung by the ohle r choir
are beautiful enough but t h e perfo rma n ce is
less interesting, and it is n ot as easy to acclim a te the ear to each of t h ese more coneent ra ted pieces in t urn, one afte r the other, as
it is to sense t he cumulative power of the
longer Mass in its five great sections.
Blanchard: Te Deum (1745). Soloists,
Chorus of Radiodiffusion-Television Francaise, Lean-Marie Leclair Instr. Ensemble,
Fremaux
Westminster XWN 18692
H ere's another in the French-produced re"iva ls of older F ren ch music, recorded by Westmin s t er' s Erato affiliate. Blanchard was one of
a later period of brilliance at the French court,
in the da ys of Louis XV- the times of Bach
and Handel in other lands.
The 'Te Deum is a big piece, as usual only
recently dug up out of the library. For cars
acc ustomed to Bach and Handel it will have a
curious fiavor , sometimes sounding Handelian
or like Ba ch (it is closest to his Magnificat),
more often f ull of the more leisurely, low·pressure gracefulness of French musical a r t. '.rh ere
nre periodic choruses here, alternating with
groups of solo pieces or duets- two tenors,
t wo so pranos, a contralto and a baritone--with
obbligato instrumental solos to go with them .
In the big, impressive numbers a trumpet part
adds pomp and cir cumstance, mos t decoratively.
It's not a profound piece, this, nor was it so
intended (it was a victory celebration for the
winning of a battle by Louis XV) but it is
la rgely pleasurable a nd only occasionally u bit
routin e, in a showy way.
4. BIC VOICES
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64
Mark Reizen sings Highlights from "Boris
Godunov (Mussorgsky); II Aleko" (Rach.
maninoff). With other soloists, chorus, orchestra the Bolshoi Theatre, Bebolsin,
Golova·nov.
Monitor MC 2016
Chaliapin sings "Boris Godounov," other
Russian Operatic Arias. (Recorded J 9253 J).
Angel COLH 100
In spite of the mixed-up titles and assorted
spellings on these t wo discs, the main theme
is clea r enough- a brand-n ew Russian basso
a nd t he great a ll·time master, Chaliap in , sing
from Mou ssorgsky 's (.ou r spelling) great opera
- plus t idbits of this and that to fill up t he
extra space.
The compa rison is most interesting. Anyone
who ha s fo llowed recorded mu sic these last
th irty yea r s will h ave h eard the ultra ·famous
Chaliapin r ecordings of "Boris"- with the
well-relll embered groan s, grunts, rending s ighs,
ghastly death-agonies, as t he Tzar Boris expires in sta rk mu sicul form. 'The present·day
basso , Mark Reisen , sings some of the same
passages. What a differen ce! In Chaliap in ' s
days- whi ch ex t en d back into Moussorgsky's
own time--the r ole of Boris wa s s un g with
extraordin ury freedom to act and emote, in
the fia mboya n t style of the day. Never will
you ha "e h eard su ch death-rn t tl es as are
Cha liapin' s! The famo us interpretation seems
to us- if we haven ' t h eard it before--exaggerated in t he mann er of many an old movie; for
Cha liapin was the John B a rrymo re of Ru ssian
opera. But this was the per for mun ce that
shook a generation of mu sic-lovers and operagoer s and it remain s a tremendo us force in
mu sic. if now stylistically outdated.
Mark Reisen is t h e modern interpreter of
('he sa me .,m.usic and··so are · his vocul cohor ts,
whose _numes .n·re too lon g to 'spell out here_
They preserve -much of the stark, sombre tradition of great Moussorgsky performance but,
in the modern manner, they do far m or e onpitcb s inging. put on fewer a nd less exaggerated histr ionics. '.rimes have chunged.
AUDIO
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•
SEPTEMBER, 1958
'.
The Monitor disc is a good one, t he presentation as fine as any t hat now is available in
terms of present-day singing. Don ' t mak e t he
mistake of thinking it is an " eithe r'or" proposition , as between t h e immorta l Chalil). pin a nd
the present Bolshoi Theatre artists. Far from
it. Trndition must move a nd grow to stay
alive; it is not possible to sing as did Cha liapin, t hese days-thougb to hea r him " in pe rson" ,vi ll a l ways be a rare experien ce, yia
these beautifully resto red reco rdin gs.
Russian Art Songs (Balakirev, Borodin,
Moussorgsky, Cui, Rimsky-Korsakoff,
Rachmaninoff, Tchaikowsky, Gretchaninoff). Maxim Karolik, tenor, vorious pianists .
Unicorn UNS 2 (3)
A monunH~nt n(-. i-ecordrng . ·project. energetically ca rried out, this ·thiee-d isc .a lbunf covers
a fi ne collection of Russian siings. _.q): the last
centu ry, sung witb greilt ·drama ~i il:'lhe or iginal
Russian. An in ter.esting a·od' extensive ·booklet,
with a ll of the texts in English, makes fo llowing the sense of th is music unusually easy.
That highly-colored, "speaking" quality of excitement in Russian song, so easily lost in
translation, is brought out magnificently by
Maxim Karolik, who explains in his preface
t hat the singing-a rtist-as distinct f rom the
mere s inger- must h'a ve as his motto, "Listen
to what I am saying with my voice." It is that
speech, even in a strange language, that carries us t hrough this a lbum with growing interest as the many songs fo llow one another.
It is, t herefore , merely incidental to the
main impact of the singing that Mr. Karolik's
musical ea r turn s out to be somewhat less
than accurate, and easily t hrown off by u nexpected twists of Russian Romantic harmony!
At times, voice and piano simply part company, un t il the new ha rm onic path is fo und
by the wandering vocal instrumen t.
Yet I am h ere to say that, in a case like
this, good drama and a h igh sense of diction
can make up for a bad ear. I enjoyed Mr.
Karolik an d I found a n ew res pect for his
numerous com posers' unusu a lly powerful songs
-which is surely what Unicorn had in mind
when t he a lbum was made.
Robert Pettitt is the excellent piani s t In
most of the work s, but two others spell him
fo r a so ng or two, here a nd the re.
Nicolai Gedda-Mozart Arias. Paris Conservatory Orch., Cluytens. Angel 35510
Well, Nicolai Gedda is s upposed to shed the
resplendent lustre that comes with a contract
at the Met ( 195 7- 58) a nd he has been one of
t he last season's highlight voices. But here,
on my first h earing of his voice, h e t urn s ou t
to be a shallow a nd colorless Mozart singer.
His best, I g uess, is "Dalla sua pace" from
"Don Giovanni" of Mozart, whe re he s ui ts the
smug virtuous ness of the somewhat mealymouthed Don Ottavio-Mozart's fo il for lusty
Don Giovanni himself.
I n short, just another fi ne tenor , complete
with golden tone, beefy phYS ical proportions,
yet lack ing in a ny so rt of communicative
musical intelligence, at leas t iu th is music.
And hi s father was a Don Cossack, too!
Mahler: Songs of a Wayfarer.
Brahms: Seven Songs, Op. 32. Dietrich
Fischer-Dieskau; Philharmonia, Furtwangler; Hertha Klust, pf.
Angel 35222
Mahler: Lieder eines Fahrenden Gesellen
(Songs of a Wayfarer); Kindertotenlieder
(Songs on the Death of Children). Kirsten
Flagstad; Vienna Philharmonic, Boult.
London 5330
Here are two impressi ve vocal records, overlapping in t he songs-w ith-orchestra by Mubler--the most personal, t h e most poet ic Romantic composer after Schubert.
Fischer-Dieskau is the fin est German baritone of the yo unger generation a nd the reason
why is easy to hear-a fine vo ice, plu s a t remendous mu sical intelligence and an emotional
power t hat hits to the very depths of these
Bongs. (Like German songs wi t h piano, the
Mahler works can· be s ung by va rious ty pes of
voice, male or female . )
Generally. it is harder for us to get the
sense of this sor t of music via a male voice
(Continu ed on page 77)
AUDIO
•
SEPTEMBER, 1958
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65
Noises Are Expensive
HAROLD LAWRENCE ';'
T
have aheady set up the
players' seats and stands, and the recordiug crew is now busy laying out
cables and hanging micl'ophones, Thirty
minutes or so before the start of the ses·
sion, the musicians begin arriving; violinists can be heard limbering up their fingers
with snatches of the Mendelssohn and
Tchaikovsky concertos, the harpist goes
thr ough the elaborate process of tuning her
instrument, and the first desk men who
have solos are practicing for· their big moments, Finally, the personnel manager
herds the orchestra on stage, the conductor
strides out on to the podium, greets his
players, and the session is about to begin.
If all goes well, no extra-musical sounds
will crop up to affect the proceedings
seriously. Unfortunately, sonic gl·emlins
have a way of intruding on recording sessions, despite all advance precautions.
By way of illustrating the kinds of unwanted sounds that harass recording companies, the preceding mythical session will
be sprinkled liberally with the more common varieties of noisemakers.
Humidity and temperature are known
to affect the acoustics of a hall in terms of
brightness and resonance. These factors
can be responsible indirectly for less subtle
aural results. The time of the present session is nine a.m. It is a chilly March day.
Because the stage lights were switched on
only moments before the recording was to
begin, the first 25 minutes were marr ed by
cracking filaments. Outside the hall, the
weather has taken a turn for the worse.
Dark clouds are forming overhead, and the
wind and the rain quickly fo llow. Inside t he
hall, the sensitive microphones pick up the
gusts and raindrops in pianissi1/W sections
of the music.
The storm now subsides and the men in
the control booth breathe easier. Suddenly
the microphones begin transmitting a serie's
of low-f requency sounds which are obviously not called for in the orchestral score.
A rapid investigation reveals that t he conduct or, carried away by the rhythmic excitement of the work, is vigorously st amping out the beat with his right foot. In·
fo rmed of his misbehaviol', he decides to
get off his feet entirely so as not to risk
a repetition of t he noise. A new number is
slated and the session moves along. Minutes later, during a vitally important and
tricky bridge-pasage leading to a new section of the work, odd squeaks begin to
emerge from the playback speakers. It appears t hat the stool on which the conductor
is n ow seated is a rickety antique fit f or the
woodpile.
HE S'l'AGEHANDS
CONVERTS UNDISTORTED
OUTPUT INTO
UNDISTORTED SOUND
New .
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thin . . . s trong es t, m os t
rigid cone mate rial kno wn
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Concept that match es . .. and sur-
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passes the un w ieldy and ex p e nsi ve
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" HOLTON I I s y stem that offe rs " big "
sy ste m performance without unn ecessa ry twee ters, wo of e rs and cum be rsom e " cross -overs", The HOLTON
is se nsibly-s ized and b e aut ifull y
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Compare
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"Take Five"
F urious at being interrupted so many
times, and annoyed with himself for having
* 26 W. Ninth St., New Y01')c 11, N . Y.
66
been the cause of the l ast two incidents, the
maestro asks for and gets a break, in ol'der
to regain his composure.
During intermission, the stagehands remove the stool and place a carpet on the
podium, Alone in the artist's ~'oom, the cond uctor paces the floor.
The clanging of a bell indicates that it
is time to get back to work. The personnel
manager claps his hands, gets everyone
on stage. Up on to his sound-treated podium steps the conductor who lifts his baton, and waits for all rustles, squiggles
and conversation to stop. But he does not
give the down-beat- an airplane motor has
just broken the silence of the hall. As it
dies away, the stick goes up again, to be
interrupted this time by a call from the
control booth. The drone of the engines
has been replaced by a mysterious hum,
and could t he maestro "bear with us while
we try to locate it~" The stage manager,
accompanied by the recording crew, rush
out. The SOUl'ce of the trouble is the blower
system, which had not been turned off after
the intermission.
The now restless conductor faces his
players, grits his teeth, and at last succeeds
in giving an unbroken down-beat. But now
the sound of distant chimes is heard in the
hall. Since the wOl'k being recorded is not
Night on Bald Mountain, D1'eam of a
Witches' Sabbath (from Berlioz' "Symphonie Fantastique"), or Danse Macab1-e,
and since t he percussionist isn't touching
the chimes, obviously t hese bells are intruders. They belong to the Town Hall's
clock tower, and are r inging the hour.
Among the extra-musical sounds produced by musical instruments, the fixing
and removal of mutes is a familial' one. No
one notices them during a concert performance, b ut it is a different matter iu a recording session, especially when the music
is quiet. In the present mythical session,
t he affected secti on was played twice; the
first time with mutes, going on beyond the
point at which mutes were to have been removed; and the second t ime without mutes,
proceeding without interrupt ion. In this
way, the noise of mutes could be thoroughly
eliminated in editing the tape.
Although barriers were p osten out sine
t he hall to divert traffic, one annoyed driver
who had taken the wrong turn and found
himself confronted with a closed-off street,
did what so many motor ists do when faced
with delays : he sounded his horn. This was
of cour se picked up in t he hall, as were the
shouts of children being let out of school
down the block.
Before the session was over, a door or
two had slammed shut somewhere up in the
balcony, a vacuum cleaner whined in the
corridors, several members of the orchestra
sneezed or coughed, and the conductol' forgot himself and hummed, grunted, aud sang
as he worked.
AUDIO
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•
SEPTEMBER, 1958
Why Bother?
The difficulties encountered in this imaginary ]'ecording session would have long ago
exhausted the patience of even the mildestmannered of conductors. That all of these
mishaps could occur within one session is
highly improbable. Yet, taken individually,
none of them is a rare phenomenon when
recordings are made in a concert hall, theatre, church, or town hall. Why then, you
might ask, are recordings made in these
places when there are insulated recor ding
studios available i
First, the studio has yet to be built that
can rival the acoustics of Chicago's Orchestra HaU, London's Kingsway Hall,
Amsterdam's Concertgebouw, or Vienna's
Musikverein. Second, an orchestra is
generaUy more at ease in the familiar
surroundings of its own home, and for other
than purely sentimental reasons. T onal production is intimately related to acoustics.
In a 'dry' hall, musicians play louder and
more forcefully in order to overcome the
sonic limitations; in a more resonant room,
dynamics are enhanced, and they can play
tr uly soft passages without the danger of
slipping into inaudibility. Acoustics play
a basic role in shaping an orchestra's personality. Therefore in order to preserve this
personality, many record companies prefer
to visit the oI'chestI'a in its own home,
rather than take it to a stndio. As for
these extl'a-musical sounds, what's a little
lloise to a 'big sound' ~
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67
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CHARLES A. ROBERTSON .:'
STEREOPHONIC
Erich
Vol. 2
Kunz:
German
University Songs,
Vanguard VSD2009
Jimmy Rushing: If This Ain't The Blues
Vanguard VSD2008
One of the advantages enjoyed by an independent record firm is mobility and the ability
to change direction at the first shift of the
wind. These two stereo items not on ly mark
the entrv of another label into a fast growing
field, but"also are representative of the mastering pra ctices of two major companies. Acting
on its prerogative as n free agent, Vanguard
allotted a portion of its initial stereo disc release to the custom depart,nen ts of both Columbia and RCA Victor.
The Gerlllan University Songs, hanoled by
Columbia, are ideal for the n ew medium in its
present stage of developmeut. The settings are
varied and impose no overmodulated passages
on the grooves . The suave baritone '·oice of
Erich Kunz is balanced by a male choru s which
spreads to the two loudspeak ers when not supporting th e soloist. As conducted by Anton
Paulik, the Orches tra of the Vienna State Opera remains mostly in the background. When
a harp is brought to the fore, it seems centered
between the sound sources, effectively tying
them together.
'l'he fraternal harmonies of the songs are
quick to create an illusion of the high hills divided by the Rhine, rather than the concert
hall. Their outer limits evade spatial limitations, and the voices dissolve pleasantly in the
distance. Much of the stereo interest stems
from the different ways in which the forces
involved are employed by the arrangements.
As each variation opens new possibilities, the
attention of the listener is consistently engrossed.
'.rhe bullnecked blues shouting of Jimmy
Rushing is more firmly embraced by the phrases
of eigh t stellar instrumentalists in the
stereo version mastered by RCA Victor. The
virtues of the session were detailed in these
pages when it first appeared on LP, and it is
packed with the vigorous jazz interplay that
has proved so adaptable to stereo. The electronic organ which competes with Rushing can
be balanced to suit your taste, and the guitar
of Roy Gaines serves to hold the rhythm section together.
If the German Songs seem more successful,
they a lso presented fewer problems. Both discs
have adequate volume level and distortion is
kept within bounds. They reached the stores
about a week before the first Victor releases
and preceded the initial Columbia offering by
a" longer interval, illustrating another aspect
of the independent's capacity to move fast.
According to Vanguard engineer John Beaumont, who was engaged iIi · itS " recorded-"·tape
program from its inception, ·the company · fs
keeping alert to all developments in stereo.
Like every other" label in the industry; it ""is
still feeling its way in the .stereo disc "field.
One of the "pioneers of ··stereo tape, it his~bi"rnt"
a substah"tliil 'Catal()gue. :For· lhe-· past ·~evefal
~ears, all sessions ' in its stuilios' in this·" coun-
*7-32 Tile Parkway, Mamaroneck, N. Y.
try were recorded in stereo. It will use th e exp.erience gained in the process to seek out and
employ the best techniques for tmnsfering
them to discs.
Dick Marx: Marx Makes Broadway
Omega Disk OSL2
Somewhat of a fixture in the recordec] tape
industry, Omega is adding a catalogue of stereo
discs to its line. Of the first four items received,
the jazz treatment of Broadway show tuues by
Dick Marx is most successful. The young Chicago pianist, in one of his rare journeys away
from his native city, joins a group of Los Angeles musicians in ten hits of such caliber a s
Leonard Bernstein's 0001, Just In Tillite, and
Too Close for Oomfm·t. His flexible piano worl'
is nicely balanced by the flute of Buddy Col lette. Red Mitchell alternates with Carson
Smith on bass, and Howard Roberts and Irving
Ashby share featured roles on gnitar. The quartet is in the lyric modern vein, and the swift
interplay
becomes
espeCially
rewarding
through stereo.
Paul Tanner, a former trombonist with
Glenn Miller, plays an electro-theremin on
"Music For Heavenly Bodies," (OSL4) . Developed to his specifications, it boasts a measured
frequency range from zero to better than 20,000 cps, and its sounds are pure sine waves
without any harmonics. Unlike a theremin operated by hand motions, it works on a slide
and is more accurately controlled. Andre Montero's Orchestra backs the eerie melodies in
astronomic mood settings by Warren Baxter.
Another mood item is Lloyd lI1umm's Orchestra on "Champagne Music for Dancing,"
(OSL1). Heinz Sandauer conducts the Omega
Orchestra on Leith Stevens' dynamic score
for the movie "Destination Moon, " (OSL3).
The Stereo Disc
Capitol SWAL9032
Capitol Stereo Demonstration Record
the event, but they are not lacking in interest.
The Manbattan subway train is easily identified as belonging to the IND, rather than either
of the alternate lines. A slumbering Diesel engine is roused in to action and moves ponderously out of the yards. A New York ferry boat
smacks comfortably into its dOCk. There is a
sequence in a bowling alley and one of children
returning from school. Only the crowds in
Times Square celebrating New Year's Eve
seem a little artificial. They hardly ever come
tha t boisterous anymore. A track for balancing
speakers uses the sound of" castanets.
The musical samplings cover the entire range
of the catalogue and aim at "creating an even ,
natural display of sound all across the 'stage'
in front of the listener." This seem s to be a
characteristic of the items recorded a t Capitol
'l'ower·. Not only is there no drop-off of sound
. in the middle, but there is no excessive amount
o"e "presence centered between the two speakers,
·"as is found in some three-channel efforts. It is
a ~quality. es·pecially evident in" numbers by the
RQge·" Wagner Chorale and Fred" Waring. The
highs are clean and clear, even to the hiss of
air so essential to Ernst Toch's SIJ·m phony
No : S. Nat Cole, Stan Kenton, and Jackie
Davis all appear, in addition to Carmen Dragon
conducting the Hollywood Bowl Orches tra .
The side given over to music runs roughly
twenty-two minutes, a goodly length for a
stereo demonstration disc. The sound is excellen t and cannot be distinguished from that on
the promotional sides. As a briefer program
is desirable and the wider cut will permit the
harsher handling anticipated, these are shorter
by half. Classical bits fill one side and the reverse is devoted to Les Brown, Harry James,
Les Baxter, Billy May, and others on the
Ca pitol roster. Never have the big bands
seemed more live.
When compared to the London demonstration disc or those mastered with a Fairchild
cutter, our two main reference points at the
moment, the reaction is wholly f a vorable.
There is a little less gain , but almost no technical deficiencies distract from the music and
distortion is at a minimum. If you attend a
High Fidelity Show this fall, you will hear
just how far the stereo disc has advanced in
less than a year.
MONOPHONIC
The Music Of New Orleans, Vol. 2
Folkways FA2462
'l'he subject of the second volume in a series
devoted to the traditional sounds of New Orleans is the Eureka Brass Band, the largest of
the marching bands left in the city and the
one closest to the legendary paraders of the
past. Organized about 1920, it outlived llla uy
of the older ba"nds and survived the depression
to enjoy its best years after 1936. Its jauntier
tunes are part of the standard dixieland repertoire and have achieved wide circulation ,
but the a ctual units are more amply covered
in print than by recordings. These are somewhat of a rarity, and the Eureka partiCipated
seven years ago in the only previous one not
made by a group hastily organized for recording purposes. Because the setting was then an
open courtyard, the sound is diffuse and little
of the impact of the band is felt. Such "is not
the case in the present venture, recorded in a
meeting hall on Dryades Street, last March ,
shortly after Mardi Gras Day and the Zulu
Parade. When the band begins to roll with resounding bass drum and sousaphone on Just
A. Little While To Stay Here, the wonder is
that the equipment stayed in the room.
Samuel B. Charters bri efly ou tlines th e history of the brass bands in his notes, touching
on the changes in instrumentation which
brought into the Eureka the saxophones of
Manuel Paul and Ruben Roddy, a veteran of
Walter Page' s Blue Devils, in place of baritone horn and clarinet. The trombone team of
Albert 'Warner and ' Sonny Henry, who a t 72
is the oldest member, overflows with good
With the entry of Capitol into the arena
la te in August, all of the majors and a goodly
number of independent companies are represented on stereo discs in some form or other.
To introduce its new product and disseminate
advance information on its quality, the label
has prepared two demonstration records, both
narrated by Art Gilmore. One lists to sell at
the usual price of an LP, and the second is not
for sale, being allotted to distributors and
dealers to promote the merits of the firm's
line of packaged stereo equipment.
Their combined total is an impressive array
of excerpts, with only one duplication-the
mighty impact of a train at an unidentified
railroad crossing. Several artists and groups
appear on both, the honors going to the thrice
heard Concert Arts Orchestra, under Felix
SIittkin; playing Britten's Young Person' s
Guide to the O,·chestra. In the part devoted
to the- percus"sion . section, stereo separation
spil'its .on the . ragthne piece T1'o'tnbon1UUl" and
works its wonders and, for once the tympani
fluently snPPol"ts the trumpet of leader Percy
fail · to -overpo~ver the s!;rings.
Hm:i1phrey on Lord, Lord, Lord: One of" the
This·interlude_is .ass"igneu "to· the paying cu"splayei:s is "aJwaYS -Cal"l'yiilg the · melody as the
"i:omers who, on tlle· whole, rec";":e·· the liest . ·-batH] improvises on Mar-vIand, and· a less ably
value. Fewer h/U"d-sell tactics are employed · in
recorded -rehearsal ·of Panallw. A quieter moannouncing ·the examples chosen to acqutiin t" ,llent comes with the fimeral ilirge Eternity,
them with the new system of home entertaina n intense and difficult lament in four strains,
ment. The sound effects are there to dramatize
a nll its eloquent trumpet solo by Willie P a-
AUDIO
68
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•
SEPTEMBER, 1958
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SEPTEMBER, 1958
69
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jeaud. The Ampex 600 and E lectro -Voice 655
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The Ward Singers: Meeting Tonight
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DIaranlz «:o ... pan."
25-14 Broadway, long Island City 6, N: Y,
folk singers in the gospel songs of The Ward
Singers, the most ou tstanding of seve ral such
worthy groups based in New J ersey. A pure
passion a nimates thei r every phrase, in contrast to the blatant emotion of rock abd roll
or tI\e devitalized sentiment Qf much pop singing. One s ide recoristructs a · tent-covered revival service, with th<'! group singing Tenting
Tonight On 7'he Old Gamp G,·ou.nd to introduce featured soloists on The Lo·r d' s P,·aye·/·,
Swing Low, S'weet Gha,-.iot, and a wordless lament by Gertrude Ward on Amazing Grace. A
recital of spi rituals, in fo rcefu l arrangements
which place them in the private preserve of
leader and pianist Clara Ward, fills the reverse
side and includes A Step To Make, I 'I! Be
'l'he·,-e, and Blessed Are They. Robert Banks is
organist, and drummer Buddy Mack Jones
matches the varied and moving r hythm patterns of the g roup. None of its heady excitement is lost in the recording.
AI Hirt: Swingin' Dixie
Audio Fidelity AFLPI877
Based at Dan Levy's Pier 600 on Bourbon
Street, the Al Hirt band also wakes the Delta
with a morning radio show . It presents a
unique amalgamation. of swing and dixieland,
operating much as might, in a playful moment,
one of the smaller fo rces that Harry James
or Lionel Hampton drew from the Benny Goodman organization in the late '30s. The leader's
trumpet is fiery und brilliant, roistering along
the path of the powerhouse stars of the swing
area. To showcase it and the work of other soloists, t il e band prefers fast tempos and loo selywoven dixieland en sembles to repeated riff pattern s. It strives for excitem ent and attains it
through swift changes of mood, th e sudden
climax and a chargin g rhythm section.
'I.'hree members were formerly led by George
Girard, the New Orleans trumpeter who d ied
last yea r of cancer. They are Bob H a vens, a
trombonist in the Brunies' tradition even to
maneuvering the slide with his foot, bassist
Bob Coquille and drummer Paul Edwards. Once
clarinetist with Th e Dukes of Dixieland, Hal
Cooper i s back in his native city and with
pianist Ronnie Dupont completes the lineup .
Hirt contrasts 8kyrocl,eting 8010s on And the
Angels Sing or Big Blttter and Egg },fan
again st a quieter New 01"leans or Mississipp·;
.MII.d. A younger edition of Wingy Mannone and
Louis Prima, he has t heir zest and capacity
to dr ive a band. Edwards sets a rapid pace on
Garavan, an d Cooper sparkles on Hindltstan.
And the band ha s worked on The Saints long
enough to a dd several new choruses. Made on
location at the club, the recording dispenses
with audience noises and appla use in favor of
good sound. Stereo versions on tape and d iscs
are fo r thcoming.
Dukes Of Dixieland: Circus Time
Audio Fidelity AFLP1863
Having exhau sted a large amount of the
stan dard dixiela nd fare on their six previou s
albums, The Dukes of Dixieland a re up early
to meet the circus tra in and expan d their repertoire by catching the glamor of the big show.
There are Billboard MaI'ch and Wa8hington
Post to get the parade underway. Entry Of
The Glaaiat01-s puts the three rings in motion,
and there is a lofty Flying Trapeze. The ext ravagant attractions of the sideshows are r elayed on Ta-Ra-Ra-Boovt-De-Ay, A Vision of
Salome, and In A Persian Market .
Some of the Introductory passages find the
three Assuntos far removed f r om their u sual
style, hut before they are finished even th e
Lon e Ranger's theme is brought around to a
dashing two-beat on Swinging William. And
clarinetist Jack Maheu's solo on OVe?' th e
l ·Vaves is steeped in New Orleans tradition.
Barney Mallon, a new addition on tuba, reaches
down to the lower depths in awesome low-frequency meanderings on Asleep i n the Deep. He
switches to bass to take the Merry Widow OIl a
tour of t he midway. In their use of sound to
evoke a carnival spirit, The Dukes are unmatched on r ecords and on this trip they are
bigger and better than ever.
Bobby Henderson: Call House Blues
Vanguard VRS9017
Hu ving recalled the era of Harlem stride
pianists on his previou s effort, Bobby Henderson pays a visit to a still earlier period in this
leisurely documentation of the honky-tonk
sounds that tilled the gap between ragtime and
the matured styles of Fats 'Valler and James
P. Joh nson. It is joyous party piano, drawing
strength from countless regiona l artists and
pointing the w ay to later developments. It
survi yes, with any a uthenticity, only in the
·memories of some of the older mUSicians, a
few piano rolls and still fewer . re.cords. Where
else is it possible to hear AZexande,-'s Ragtime
Band played in march tempo, as it was treated
in 1911 ? Henderson's placement of accents and
use of dynam ics transforms it in a performance whi ch could be studied with protit by all
jazz aspirants, not just pianists. His style
may seem remote, bu t his methods will never
be outdated.
For Henderson gets u nder the surface of a
tune and takes his audience with him on
Diga-Diua-Doo, Land Of Jazz, and A Good Mati
I8 Hard to Find . He always uses two fnll
hands , guiding them with audible humming,
ancl builds a smoldering blues atmosphere on
his title piece. There is a diversionary Miss01wi Walt z, matched by the tinkly rhythm s
of Tlwee O'G lo ck itl the .Mo,-tting. '.rh e piano
has the stringy treble tones of an old u pright
and a resonant bass, all superbly conveyed in
the recorUing.
Jimmy Witherspoon: Goin' to Kansas City
BI ues
Victor LPM 1639
Jay McShan ll , the Kansas City pianist and
leader, gave ,Jimmy Witherspoon his sta rt as
a blu es singer in 1944, and this reunion engages them on a g roup of songs associated
with the city and its jazz greats . There are
more than tive minutes of Joe Turner's Piney
B,-own Blltes, a recollection of Pha Terrel on
Unta th e Real Thing Gomes lUong, a trip to
Mary Lou Williams' F,·oggy Bottom, and three
W·itherspoon originals. The blues shouter is in
tine form and the arrangements by Budd Johnson are loose and swinging. Assembled by McShann for the session, only part of the band
h as the direct K ansas City antecedents of
bassis t Gene Ramey, but all a r e close to th e
blues, notably trombonist J. C. Higginbotham
and g nitarist Kenny Burrell. McShann 's appear a nce on an LP is lon g overdue, a nd th e
recording is free of the echoed concessions to
the r ock-and-roll fraternity whi ch marred
Witherspoon 's last effort.
Modern Jazz Concert
improvisation
www.americanradiohistory.com
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by
Bill Evans,
Art Farmer,
Jimmy Knepper, Fred Zimmerm an, and James
Buffington, indicating tha t Schuller might have
expanded his remark about the commercial
"level that suppresses creative imagination
by the stereotyped mass-appeal patterns" to
include a larger area than jazz or popular
music. George Russell conducts his AU A bout
Rosie. Harold Shapero's On Green Moun ta;n
bears the subtitle "Chaccone after Monteverdi," and Jimmy Giuffre is r epresented by
Suspensions.
AUDIO
70
Columbia WL 127
Commiss ion ed by Brandeis University and
performed at its 1957 Festival of Arts, the
six works on this record are r emarkable in the
variety of their conception. By the broadest of
generalizations, they might be called a marriage of jazz and other musical forms, but it is
simpler and more exact to r egard them as extensions of ideas with jazz origins. In addit ion to fostering the project f rom its in ception
and conducting the orch estra, Gunther Schuller brings the su bject into focus in his composition Transfor1nation, and the liner notes.
Much of hi s r easoning w ill become academic
to those who h eed his dictum that the works
" will take pa rtiCipation on the part of the
listener, repeated hearings, and an open mind !"
They are far removed from earlier symphonic jazz, ranging from the fundamentals
preached by Charlie Mingus in his Revelations
to the blocks of sound m olded by Milton Babbitt in his A ZZ Set. They seem most compelling
according to the amount of space a llotted for
•
SEPTEMBER; 1958
Charlie Byrd: Blues For Night People
Savoy MG12116
The place of the unamplified Spanish guitar
becomes more secure in jazz with this recital
by the talented Charlie Byrd, a former student of Andres Segovia and leader of a jazz
trio in Washington, D. C. Filling one side is
the title piece, an inclusion examination of
blues moods in t hree sections, at times reminiscent of the solos of Teddy Bunn. His classical training and cdncert experience n ever
impede his flow of ·deas, bu t are used unobtrusively to shape and extend them into a composition of sustained interest. The blues vein
is continued on an old favorite, once recorded
by Jimmy Noone under the title Blues My
Naughty Sweetie Gives To Me, as the reguiar
bassist in his trio, Keeter Betts, moves from a
supporting role for melodic choruses. Gus
Johnson drums discr eetly to recall his former
post in the Basie band on Jive A.t Five. With
two newcomers like Bill Harris and Charlie
Byrd to state its case, the un amplified guitar
looks to a splendid future.
Mose Allison: Young Man Mose
Prestige 7137
After introducing hi s delightful southern
sketches on his first two albums, Mose Allison
treats a sheaf of standard tunes in the same
indi vidual style. The resulting mixture of old
and new is refreshing in its element of surprise
and the recasting of familiar t hemes. His single-line piano statemen ts bear a close resemblance to his laconic, unstrained vocals on
Don't Get A.,·ound Much A.nymore, I Hadn't
A.nyon e T i ll Y011, and Let Me Hold Your Hand .
His lone composition is for muted trumpet,
played against a background of Addison Farmer's bass and the drums of Nick Stabulas. Its
title, St,·oll, is indicati ve of its ca refree nature.
Fed by his memories of co untry blues singers
and the ragtime playing of his father, Allison's roots give him an advantage over most
young modernists, though some may boa st
more technical proficiency. Like Thelonious
Monk, he always has something to say a nd the
means to say it, making him th e most distinctive new pianist to emerge since Horace Silver.
Cliff Jordan: Cliff Craft
Blue Note 1582
In its gift of saxophonists to jazz, Chicago's
DuSable High may soon acquire the fame Aust in High School boasted in another day. Among
CliO' Jordan's classmates were Johnny Griffin,
John Gilmore, and John Jenkins, all v isitors
to Manhattan recording st udio s. The young
tenorman mines a r i ch blues strata h ere, urged
on by pian ist Sonny Clark. His three originals
are formed with strong, flowing lines and contain r eflective muted passages by trumpeter
Art Farmer. They exe rcise their ingenuity on
Parker's Confirmation, and a faster paced
A.ntlwopology. J ordan, with Clarke and bassist
George Tucker, makes a beautiful solo veh icle
of Sophist'icated Lady, impinging on her more
ear thy qualities. Louis Hayes is on drums.
Recent PRESS COMMENT on the AR-2
audiocra-Ft-
(jos e ph Marshal/)
"There are many systems, both large and
sma ll , whose claimed or casually mea sured
cu rves will match at of the AR·2 ...
The paradox is t ·
..h
most of these th
material, seems t
an octave lower.
" ... low di storti
octave rof bas
prefer, .. . di st,
n
from speakersJWith s
re sponse cur"'~s.."
ell)of l'I!(:III:tled
I'Oll',
l,t " ",uS,,:
/
(Fred Grunfe/d)
" ... too much ca
little AR·2' s .. . t
natural qual ity- ,
metallic timbre /tlla
top·ranking s pe~k er s
the answer fo r! anyon
a very clean"stri ng t
THE DIAPASON
(joseph S. Whiteford)
" .... the problem
low frequency or
or coloration wa
'El ectronic' soun
Reseal ch speake
insta lled perm
reverberotio
vi
Cambridge, .' a ss. ·1
ideal sol utiontl!_
/
Hal McKusick: Triple Exposure
Prestige 7135
Because of his concentration on the alto
saxophone in r ecent years, the playing of Hal
lI1cKusick seemed fairly static in its references
to Lee Konitz and Charlie Parker. Nothing h e
does here on the instrument moves him from a
category somewhere between the two, but he
essays his first recorded solo on tenor, choosing a warm sound suited to the Basie-styled
S01l.ething New, a nd featu res hi s clarinet on
three numbers, as he did when with Terry
Gibbs seven years ago. Two of them are his
own compOSitions, a blues and the vernal A.
7'01/.ch of Spring, and provide a creative base
for his pleasant, melodic solos. They open a
folk vein that he should explore further, as
his ideas become more individual a nd his tone
i3 liquid and full. After a period spen t in
France working as an arranger, tro mbonist
Billy Byers marks his return with an ex ultant
war whoop on The Settler and I 'he Ind'ians.
Un ison chording by pianist Eddie Costa paces
the rhythm section of bassist Paul Chambers
nnd drummer Charlie Persip.
PLAYBOY
(john M . Conly)
" One except ion t
a sin gle-con e u
speake r system
AR·2, at just un
speaker (tweeter an
woofer), of extfaordin
It is definiteJy,.-a barg
AR-2 acoustic s,!spension speaker systems are $89 to $ 102, depending on
cabin e t finish . Literature is a va ilable for the asking .
ACOUSTIC RESEARCH, INC.
24 Thorndike St., Cambridge 41, Mass.
(Conti'wlled On l)age 75)
AUDIO
•
71
SEPTEMBER,- l958
www.americanradiohistory.com
AmericanRadioHistory.Com
NEW PRODUCTS
• VU Meter. Although they meet American Standard C16.5-1954, the new Model
561 VU meter recently introduced by
Assembly Products, Inc., Chesterland,
Ohio, occupies 15 per cent less panel space
than comparable units. Construction is
s uch that only the indicating area is
exposed, the rema ining portion of the
model baffied to afford 360-degree listening. Frequency range of the entire
assembly is 100 to 12,000 cps. Power
rating is six watts. The Audiolier is
available in stake-type or base-equipped
models. Manufactured by Shalda Manufacturing Company, Inc., 156 W. Pro viden cia Ave., Burbank, Calif.
X-3
drive, switch contacts on record-playback
control for operation of external eq uipment, universa l compatibility with avail-
• Osoillator-Voltmeter. Constructed to fit
standard 19-in. rack and using only 7
inches of panel space, the Waveforms
Type 1501 oscillator-voltmeter combination Is. a complete miniaturized a udio test
system. The oscillator section covers a
range of 18 cps to 1.1 mc an d delivers 10
volts open circuit. Distortion is under 0.2
per cent. The voltmeter operates over the
same frequency range with an accuracy
So
meter being located behind the mounting
panel. For easier reading without strain,
the scale of meter is tilted upward to
reduce glare. The meter may be illuminated from behind the panel through a
strip .of translucent plastic across the top
of the sca.le section. In acco rda nce with
the Standard, the meter has a response
time for a step change of 0.3 second ± 10
per cent. Overshoot is 1.0 to 1.5 per cent.
X -I
• 'l'ransistor 'l'ester. A general purpose
transistor tester for laboratory, field, and
industrial application, the Sonex Model
TT-205 measures small signal beta, collector leakage curren t, a n rl collector r esistance on a ll NPN, PNP, surface barrier,
grown or diffused junction transistors.
Eleven operating points are provided with
one convenient selector switch. The tester
is self-calibrating and the transistor
under test is operated in a temperaturestabilized c ircuit insuring that each unit
is tested under identica l biasing conditions. The tester employs three transistors
and is powered by one battery with very
low current drain. Sonex, Inc., 73 S. State
Road, Upper Darby, Pa.
X-2
• Garden Speaker. Designed to blend n a turally into outdoor settings, the "Audiolier" is made of molded fiber glass,
weather-proofed, and is garden green in
color. It is easily connected as an extension to indoor hi-fi or intercom systems.
The speaker unit is a 6-in. extended range
of + 3.0 per cent. Twelve overlapping
ranges read from 1.0 mv to 300 volts full
scale. Input impedance is 10 megohms .
Waveforms, Inc., 331 Sixth Ave., New
YOl'k 14, N. Y.
X-4
~:;.
..
• Altec Lansing Mixer Amp1i1ler. Exception'a lly flexible for use as a remote broadcast mixer, in public a ddress systems, or
for recording, the new Altec Model 1567A
h as four low-level and one high-level inputs, each with individual volume controls, a master gain control, separate bass
and treble controls, and a n illumination
contro l. A VU range switch is provided
for use with a VU meter which may be
easily insta lled without soldering. Inputs,
normally high-impedance, may be converted to low impedance by installation of
the 4722 plug-in transformer. Illustrated
as it appears both in and o ut of a n
accessory portable carrying case, the amplifier may be rack-mounted when desired,
occ upying three units (5';4 in. high). Tota l
weight, including all accessories, is 22 Ibs.
For portable use an adapter provides XL
connectors for inputs and binding posts
for outputs. Complete technical information will be supplied by Altec Lansing
Corporation, 1515 S. Manchester Ave.,
Anaheim, Calif.
X-5
• Starlight 'l'wo-Speed Stereo 'l'a.pe Deck.
A new tape-transport mechanism featuring a hysteresis-synchronous motor, stereo
record/ playback heads and professionaltype construction throughout has recently
been introduced by Metzner Engineering
Corporation, 1041 N. Sycamore Ave., Hollywood 28, Calif. D esignated the Starlight
120, the new deck is designed for professional use and home hi-fi systems. Op erating speeds are 7~ and 3%, ips. Complete shielding of the stacked stereo heads
provides a signal-to-noise ratio of 60 db
and response flat within ± 1.0 from 40 to
10,000 cps or ± 2.0 db from 30 to 15,000 cps
when amplifiers employing NARTB equalization are used. Wow and flutter are less
than 0.18 per cent rms at 7~ ips; under
0.27 per cent rms at 3%, ips. Other features
include slot loading, flywheel capstan
able amplifiers, and a three-digit index
co unter. Additional information and s p eci fi cations may be had by writing to the
a ddress given.
X -6
• G-E FM-AM Tuner. Scheduled fo r a va ilability in Sep t ember, the n ew General
Electric FM-AM Tuner will feature high
sen sitivity, precision tuning, a nd an unusually low hum and n oise level. It will
also be equipped with an FM multiplex
jack for r eception of multiplexed broadcasts with additio n of a special adapter.
Sensitivity of the unit will be 5.0 microvo lts for 30 db quieting on FM, and 200
microvolts/meter for a 20-db signal-tonoise ratio on AM. A built-in dua l -purpose
tuning meter will a llow precise vis ual FM
center tuning and maximum-signal AM
tuning. The FM freq u e n cy response falls
within plus or minus 2.0 db of the FCC
standard de-emphasis curve. AM freq uency
response is dow n 25 db at 10 kc for interference suppression. The tuner will be
announced as the Model FA-11. The control panel features a textured escutch eon
with extra-size knobs, a station logging
scale, and easily-read white edge-li g hted
dial num er a ls. Further information is
availabl e from: General Eletcric Company,
Specialty Electronic Compo nents D epartment, West Genesee St., A uburn, N. Y.
X-7
• Fisher 40-Watt Stereo Amp1i1ler. Designed for use in both stereo a nd monophonic installations, the new Model X-101
Stereophonic Master Audio Control/Duplex Amplifier combines a two-channel
preamplifier-equalizer, complete audio controls, and a two-channel power amplifier
AUDIO
72
www.americanradiohistory.com
AmericanRadioHistory.Com
•
SEPTEMBER, 1958
STEREO RECORDS
Organ Symphony (Saint-Saens)
XWN 18722
The Armenian Mass
XWN 18726
The Divine Liturgy of Saint John
Chrysostom
XWN 18727
Hebrew and Yiddish Songs XWN 18728
Cantorial Gems
XWN 18729
Gayne Ballet Suite, Night on Bald
Mountain, Polovitsian Dances, Flight Of
The Bumble Bee
XWN 18731
Air (Bach), P erchance to Dream, L argo,
Solvejg's Song, Ase's Death, Morning,
The Swan, H ymn to The Sun, W altz of
the Flowers
XWN 18735
In Waltz Tempo, Waltz of the Flowers,
Valse, Rosenkavalier W altzes, Waltz,
Mephisto W altz, Waltz in A Ma jor
XWN 18736
Peter and The Wolf, Carnival of the
Animals, The Young P erson's Guide to
The Orchestra
XWN 18737
Sonatas #8 in C Minor, #14 in C Sharp
Minor, #23 in F Minor (Beethoven)
XWN 18740
Sonatas #21 in C Major, # 32 in C Minor
(Beethoven )
XWN 18741
Le Marteu Sans Maitre, Oiseaux Exotiques
XWN 18746
The Vienna Academy Chorus on Tour
WP 6088
Gospel Singing in Washington Temple
WP 6089
Hebrew Melodies in Popular Dance Time
WP 6091
PHASING
(f~' om
page 38 )
and forth rapidly as you walk, the system is out of phase.
Rumble Improvement
Considerable improvement in quality
of monophonic record reproduction can
be noted by connecting a pickup as in
Fig. 1. We have played many lateral
records through a system connected for
stereo, and if the two speakers are
different there is some illusion of separation. With the coils paralleled, however, there is much less rumble noted
in the starting and run-out grooves, and
any vertical motion of the stylus due
to the pinch effect is entirely cancelled
out. We would recommend that the
"hot" leads be shorted together for
monophonic use, either by some switch
at the amplifier, or by a separate switch
at the turntable. For instance, the filter
resistor on a Miracord can be shorted
out with a ·wire jumper which will permit the filter switch to be used as a
monu-stereo switch. We. have done this
to serve as ' a stopgap until we get
around to designing a new preamp especially for stereo. In the meantime, we
ai'e enjoying excellent reproduction on
both types of records.
There is still much to learn in the
making and playing of stereo records,
but we still remember that the LP-no'w
so uniformly excellent-was not always
as good as it is now.
IE
RADle
MAGAZINES
INC., SUBSCRIF
TlON DEPT. GBl
P. O. BOX 629
MINEOLA, N. ~
Please enter my subscril
tion to GRAVESANC
REVIEW and accompao)
ing SCIENTIFIC DEM01'STRATION RECORD.
enclose the full remittance 0
$6.00.
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AUDIO ETC
(fl'om page 12 )
LOW FREQUENCY
LOWDOWN
The Racon mode l 15 -HW, 15" low
frequency spea ke r, is now available from
stock. Production facilities have been
doubled and your sound distributor should
have no difficulty in fill ing your order at
once .
The 15 HW is characterized by ext remely high efficiency. The magnetic
"pot" assembly weighs 18 Ibs., with an air
gap capab le of supporting an iron weight
of 1000 Ibs.
It uses a patented cellular plastic surround, result ing in high compliance com bined with pneumatic damping. The 2"
ceramic voice coil is permitted large axia l
movement, without encountering mechanical restraints or magnetic non-linearity.
To preve nt " breakup" at high levels, the
mechanical rigidity of the cone has been
increased by cementing feather weight
stiffening struts to its rear surface.
The 15-HW is your best bet in a low
frequency reproducer if you're bu ilding a
two or three way speaker system. Ask your
dealer for a side-by-side comparison with
any si milar appearing speaker, regardless of
price.
Write for free literature.
SPECIFICATIONS
RESPONSE
20-4000 cps
POWER
25 w .
IMPEDANCE
8 ohms
RES. FREQ.
24 cps'"
FLUX
14,500
DISPERSION
100 ·
DIMENSIONS
15\18 x8'/z
SHIP. WT.
261bs.
NET PRICE
69.50
"'Subject to prod uction tolerances
HIGH FIDELITY LOUDSPEAKERS
G!~~J~t~
Export : Joseph Plasencia
401 Broadway, New York, N. Y.
Canada : Dominion Sound Equipments Ltd.
4040 St. Catherine St., West-Montreal 6, Que.
mercial four-track tapes, the "slave uuits" erally have an easier time, get better stereo
that record quarter-inch tapes from half- satisfaction (and better musical pleasure)
inch masters, will of course operate within
than those who elect to plunge into parts.
professional tolerances and should cause That may sound traitorous, coming from
no trouble, at least in public-but what of me, but there's sound r easoning behind it.
home equipment'
The ready-made systems may boast .such
My only question, at this point, is in hi-fi virtues as pairs of 3-watt amplifiers
respect to low-priced home equipment that
("6-watt peak") and 3-inch "woofer"
may be put out by various other com- speakers. Yet the plain fact is that each
panies who merely take over the basic of these handy home systems has been deAmpex-RCA specifications, with few strings signed as a working unit and may be deattached. As in ' eyery expanding area of
pended upon to work, at least for a while,
production, there may well be various without technical complications_ The pickshades of shoddy, quick-profit designing in , -ups match the amplifiers' needs, the speaklow-cost magazine tape equipment. Here, ers do likewise, the system is integrated,
ic seems to me, is a fine area for -trouble phased, de-hummed, as far as is co=erwith the tricky matter of mechanical tape cially possible.
The big headache in stereo component
alignment. What's more, many an honest
and sincere design attempt may turn out equipment right now is, shall I say, the
to be bug-ridden, in spite of best efforts. extensive unintentional mismatching beBuilding to a price often involves miscal- tween various excellent components-excnlations of this very sort. It seems to me cellent in themsellres but not yet standardlikely that in the first rush of tape maga- ized to the point where there is real,
zine eq uipm ent we'll run into some tronble
honest true interchangeability. It's an old,
here. A slightly wobbly tape drive (it old pr~blem; we went through all th~s years
wouldn't ha ve to wobble very far)-and
ago with the standard monophomc, onethere'd be a resulting irregular cross-talk
channel hi-fi. There, it is now solved, reas the four t r acks strayed off the straight markably well, after these many years of
and narrow path.
adjustme nt and consolidation. Components
The straight-line tape drive problem, do hook up easily, rightly, effectively, with
after all, isn't completely settled in con- remarkably little disagreement between
ventional tape drive, even for two tracks them.
or for a single t rack.
The trouble is that, superficially speakBut, to turn about again, the fact is that ing, stereo components are merely .a n exit is already practical to make a drive sys- tension of standard component eqUipment
tem accurate enough to prevent "wander- and so, on the surface, can be too easily
ing" and four-track cross-talk, yet inex- thought of as "the same." Alas, the differpensive enough for introduction into home ences, in practical stereo, ar e appallingly
eqnipment. Experience and mass produc- great. Great, worse luck, in that they are
tion, as always, will do plenty to improve mostly small, but irritatingly important.
the situation later on.
All sorts of minor problems erupt-seemI see no reason, then, why we should ingly minor. A little bit of a mismatch
!'Un into any major or inherently perma- here, another there; things that ought to
nent cross-talk on this second score, due be identical turn out not to be-speakers,
to mechanical drive trouble-though I
amplifier characteristics, equalization; outstrongly suspect that there will be some put is a little lower somewhere than it
transitory tl'Ouble here and there in the might be ideally, required gain higher than
early months. There is, as Ampex observes, it really ought to be by a bit, impedances
even less chance of t ronble via signal internot quite rightly matched . . . all sorts of
a ction between closely spaced heads. No minor misfits.
chance, I'd say, except through grossly
Stereo in plain fact has brought tremenpoor design.
dous behind-the-scenes engineering probWell . . . we'll soon know, in practica.l 16ms, such as few outsiders are likely to
terms. Sometime between. now and next realize. The results show up in these seemspring, perhaps.
iugly minor divergencies, compromises,
changes, the not-quite-matched character2. PHASED-OUT
istics, just a little different from things
in the past, which actu ally are the final
As I stalted to observe above, we are almost-heartbreaking result of engineering
now entering the birth-pang phase of prac- sweat over months and months of probtical stereo disc- that is, those of us who lem-solving.
:1l'e already dabbling, wading, or plunging
When it comes to booking up stereo cominto t he new medium to see what's there. ponents, t hen. yo u will be running into a
Most people haven't got around to worrying nest of Nagging Incidentals, minor stumabout it yet. It takes a year or so and bling blocks of incompatibility or confuIllillions in persuasive advertising to "ori- sion that can turn a hi-fi boliday into a
entate" the general mass public towards cumulatively bewildering set of frustrasomething new th at costs money, like disc
tions.
stereo.
Until we-i.e. the hi-fi manufacturing inThus, as yo u read this, there will be a dustry-can phase ourselves out of this
handful of hardy consumers who actually stage, an inevitable and quite understandown the new "hi-fi" home-type stereo disc able one, you'll find that home ster eo comeq nipment anel r ecords to match. There'll ponent listening isn't going to be all fun.
be more people who have bought into com- If you don't care a fig for pbasing and if
ponent hi-fi stereo, adding sections, duplicating existing channels, buying double co nstant 60-cps bum-music pleases your ear,
then you'll have no trouble. But frankly,
preamps and the like. Oddly, since compo-nent steteo disc got an -early start , there - my disc stereo, listening hasn't yet been
,,,ill be -more component systems - around, happy, tho ngh my predictions for the fu _
for a while, than ready-made - disc - stereo tnre .remain rosy- I like stereo.
hi-ft.
The two biggest - sets of bewildennents
And oddly, too, I suspect that the people and confusions for me, so far, have inwho buy the complete and ready-made volved those ancient and familiar problems,
stel'eo phonographs this autumn will gen- hum and phasing, both of which are a good
80
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SEPTEMBER, 1958
deal more than doubled in seriousness in
the stereo components for disc. Transitory
problems, of course. No excuse for either
one of them. Day after tomorrow, all will
be well. But not right now.
m~ntosh
Situation Fluid
•
STEREO
at
I've been working already for some time
(as all this may suggest) with three or
four specific makes of stereo cartridge, with
any number of stereo discs-official and
for sale, instead of the endless test discs
we've been playing with in past monthsand I've on hand a reputable, modestly
priced stereo d ual amplifier. (I chose the
modest price range deliberately since 1
felt that stereo problems, if and when,
would tend to concentrate in that area and
engineering ingenuity in solving them
within the cost budget would be at its most
intense.)
But in all honesty, 1 am not yet ready
to report on these products by name, model
by model. Black print is much too final,
too positive, to be realistic at this point.
Things are too fluid-not the products but
the situation. Stereo is not yet solidified,
in the area of evaluation. Evaluation means
judging a product in the light of its relations to other products, and to a hypothetical norm of "good" performa'n ce that
comes from long experience and constant
acquaintance. We can do that sort of judging with almost any kind of monophonic
equipment for the home. There, critical
standards (production standards as well)
are fairly clear, accepted, understood.
Even (1 would like quickly ,to point out)
stereo tape is now in the settled, judge, able, to-be-counted-on-for-performartce category. This is amazing; after so ShOI:t a
time. It crept up on me. But, paradoxically, 1 have suddenly realized that stereo
tape (non·magazine, H ips) has settled
down-at least for me. Surely for many
others, too. 1 know what it can do, is supposed to do, 1 can judge it and judge its
associated equipment without heart-rending
uncertainty. Best of all, 1 can listen to
stereo tape for its end-product, music,
without undue technological or mechanical
iutel"ierence, 1 can enjoy it for what , it
was nlways intended to be, a t leisure and
in relaxation.
Not so with stereo disc-yet. Thel'e are
flashes of sheer joy to be had from it
(otherwise 1 would long since have given
up in disgust!) and much satisfying, pleasing listening. But in between there is H.
to pay. Granted, a lot of it is my fault,
at least on the surface. I'm just dumb;
I don't get things right, I get tangled up
in confusions. I spent a good half hour,
one recent hectic stereo day, trying to figure out what strange stereo technique the
Vanguard Recording Society had used to
produce one of its new Beethoven symphonies on stereo disc. Believe me, 1 was
so addled at that point that 1 didn't even
notice 1 was playing the non-stereo version
of the record. The album covers are almost
identical; 1 had both versions on hand.
My fault for being a dope-but that sort
of thing wouldn't happen if 1 hadn't gone
through fifty-nine other confusions and indecisions that same day. Beethoven tends
to get thoroughly lost in the shuffle, for
the time being. Maybe the performance is
good-or bad-but what worries me most
is whether the cellos should be on Jlhe right
side or the left, whether I'm hearing music
from the middle, whether-above all-the
sound is in phase, or out of phase. Also,
whether I'll ever be able to get r,id of the
constant, nagging hum problems--'that have
risen out of the particular combination of
e1YeUID.stances 1 have at hand. Rather typical circumstances, 1 fear.
AUDIO
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30 watts power (60 watts peak). Harmonic distortion: (2()'"
20,000 cycles) 1/3% at 30 watts, 0.1% at 15 watts!. Inter·
modulation distortion: Guaranteed below 1 / 2% at full 60 watt.
peak output. Hum level In .. dlble: 90 db below rated output.
Two Inputs: 0.5 volts 500 K with gain .0ntr.1 and 2.5 volts.
Dampln, lactor: 12 or better for 4, 8 and 16 ohm output. Th.
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N.'_
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THE OUESTION: Do you know where you can find information about
the current articles in mapzines about microwaves, loudspeakers, television
rep;liring, electronic musical instruments, traveling-wave tubes, transistor
amplifiers, oscilloscopes, or any other electronic subject?
THE ANSWER:
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libraries, experimenters, researchers, hobbyists, radio amateurs, radio and TV
rep;lirmen, and anyone else connected with radio or electronics. Covers radio,
televiSion, electronics, and related subjects, and published bi-monthly as a
cumulative index throughout the year, with the last issue of the year an
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LECTRODEX-the electronic magazine index-has been expanded to include over twenty publications in the radio and electronics fields. Sold by
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Two things are dreadful about phasing.
One, it is so very hard to determine con·
sistently, so ephemeral, in the midst of
constantly changing musical sound-and
yet it is so very important. You can't tell
th e difference when you want to; yet if
you are wrong, you'll have hours of ill-de·
fined discomfort and falseness of effect in
your stereo listening, until you fix it.
Secondly, wrong phasing is so very sim·
pIe and yet so devilishly hard to locateit can happen in so many places, both
legitimately ancl not-so-Iegitimately. There
. are dozens and dozens of possibilities, even
snch unthinkable (but likely) matters as
reversed phasing in a master recording
tape, or in the recording amplifiers, or in
anyone of the many tape-playing steps
beto?'e there is a thought of a disc master;
or in the clisc cutter itself.
Or in various types of supposedly
simon-pure commercially-released home
stereo equipment. Witness my fine RCA
Victor Stereo tape player, described here a
year or so ago, which arrived from the
factory with its speakers out of phase.
(Or was it somewhere else, inside ~)
The worst-the very worst- thing about
phasing in stereo is that it depends 99
percent on the ear. Very seldom can you
check it via a strictly electrical or mechanical test, minus listening. An out·of·
phase sound is just the sort of audible
subtlety that is most easily ignored by 99
percent of the technicians who deal with
stereo equipment. They can't hear the dif·
ference, can't take the time, or haven't the
curiosity, to study it and learn what the
difference is; and therefore they simply do
not talle phasing seriously. Hence- phasillg
trouble, here, there and everyWhere.
They should take it seriously, those who
have any hand in the matter. It makes all
the difference. The difference, that is, be·
tween satisfactory stereo listening and
false. It is the sort of difference that a
rank outsider, a musical amateur, will dis·
concertingly spot .for you on the instant,
where a hardened critic like myself may
have been overlooking it for days.
I had this happen to me on three occa·
sions last summer. Two of the people had
never heard of stereo-but they were right.
The third was ed itor of one of our copublications in hi·fi and he thereby earned
his medal as a goor1 Hi·Fi Ear, as far as
T was concerned. (These people spotted the
out·of·phase RCA Victor machine, each in
his or her own terms. The amateurs de·
scribed the out·of-phase effect itself, accurately, though not knowing what it was.
The editor just said "it's out of phase."
It's subtle but devastating, this phasing.
You can't hear it at aU whell you're tired
or out of sorts or discouraged or confused,
or fed up with the kids or acid indigestion
or traffic jams. Your mental ear just shuts
up and doesn't hear-or everything seems
out of phase, right or wrong. The best
hours for phase testing are between 8 and
11 in th e morning. You are fresh in mind
and body, you r ears still have that sound
of bacon frying in them, the daily routine
is not yet wearing you down. Later onyou can't be sure. Sometimes you can tell,
sometimes you can't. What seemed right
at 11 a.m. is horribly wrong at 3 p.m. You
are uncertain. And yet the phasing 'must
bo right, you 111u ,t fit it. Or you'll go crazy
trying to figure out why your stereo sounds
wrong, wrong, wrong. Yep, it's really a
problem.
And the goad that sticks into your back
is that you have always that 50 per cent
chance of being right, ,villy·nilly. Is it
right because it is right- throughout your
stereo system ~ Or because the sum-total
of eight or nine phasing mistakes hAppen s
82
to come out correctly phased' Not a pleasing thought, and you can't ignore it as
academic; chances are that when you
switch to some other medium, some other
record, some other cartridge, you'll be in
the phasing soup for fair.
It's here that I'm presently going nuts.
I want to be right ALL the time, and not
by any fifty·fifty accident. The way things
are shaping up now, I'd say I'm right
maybe 52· per cent, allowing a whopping
two per cent for deliberate, calculated,
checked correctness. The rest is happen·
stance. Each time I think I've got phasing
licked, a new contradiction pops up and I
start all over again.
The most exasperating part of the whole
problem is the way it I_eeps popping out
improbable contradictions at you, spring.
ing unforeseen traps, confusions, redun·
dancies, until you don't know whether
you're coming or going. Maybe I should
say, whether you're in phase or out. (Am 1
out of phase, or is IT f )
For instance, here's one of my unresolved
little phasing mysteries, as of this moment.
I found out that a certain highly reputable magnetic stereo cartridge was in phase
for stereo sound, dual·track, but that when
I switched to one track alone (in both
speakers) the sound was out of phase.
Same with my radio input or any standard
mono cartridge-when they were ill phase,
from the two speakers, the stereo cartridge's
stereo sound was out. I have a phase switch
in my speaker liue, of course, to check AB
on these matters. (So should you.)
No doubt about it-I've checked this
again and again. To shift from playing
stereo to playing th e radio through both
speakers (or to a standard monophonic
cartridge) I have to change the speaker
phasing. Why~ I really don't know. I'm
no chess player nor a mathematical game
fan. Maybe you are- in which case, you
can try it out for yourself, on y6ur own
equipment. I'll bet you I'm right.
(See page 38 to?' some possible explana·
tion. ED.)
A simple reversal of phase can happen
in so many, many places! I had already
checked two pairs of speakers. One pair
(still nameless, for this month) · was definitely opposite. The other pair wete identical. Or maybe the first pair was ideutical
and the Eeconcl pair opposite- for my
equipment ~ It's all relative. Anyhow, iu·
dubitably the two pairs were different. One
I hooked up with the connections the same
on both units, the other with the connec·
tions opposite .. .. Then there's the amplifier-or amplifiers. Two circuits, switched
together in all sorts of combinations. How
do I know what goes on inside that mass
of interconnected complexityf Output trans·
formers ¥ They could be oppositely phased
- why not. Or could they'
And, of course, there are my own hOllle
connections. Yep, it turned out that my
two stereo arms were hooked up with the
cha111lels r eversed. ViThat came out "right·
speaker" on one arm was "left'speaker" on
the other, until we corrected this. But
phasing'
We've gone over every foot of yards of
hookup wires, we've color-coded connections,
tested circuits electrically, and I'm sureI thin7c-that what goes in one way comes
out the same way. But there's always a
tiny, gnawing doubt in my mind . .. one
slip, one connection overlooked, and the
whole system is 180 deg. out.
I don't know the answers to most of
these nagging doubts on phasing, at this
stage. I haven't had the patience to try all
my equipment, systematically, and keep log
books on what happens. I haven't tried,
for instance, to find out whether a ceramic
stereo pickup also produces the curious
phase·reversal noted above with the two
AUDI O •
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SEPTEMBER, 1958
magn etics. I haven't tried my two ceramics,
to see whether they act alike. Dollars to
doughnuts they won't, and the fault might
be mine, in the connecting, or the maker's,
in the making.
I just don't have enough ear left.
Correction: I had just barely enough ear
left to listen monophonically, in a simple,
happy state of bliss minus any phasing
complications at all, to the vast number of
non-stereo discs you'll find reviewed in this
mont h's Record Revue. So far, I haven't
listened to disc stereo; I've listened m ainly
to phasing. And I'm tired of it, I can
tell you. Also to hum.
3.
*
Ho-Hum.
I will effuse briefly on hum; it is a subject th at oughtn't to be mentioned in polite
hi -fi circles. It is my mo st cordial hate,
above all other sounds.
Stereo hum is just around the corner in
a gr eat deal of present component concAtenations. At the present moment, I hear
hum on all stereo disc reproduction, with
All my cartridges (in different ways, degrees) and in all possible set -ups, using the
presently un-named stereo amplifier. Some
aspects of my hum are still inexplicable
tc. me- various myst erious ground-loops
and the like that defy detection. Other hum
situations I have cleared up in part, r educed the hum to a satisfying degree, without quite eliminating it.
But what gets me down is th at with any
one of a half dozen fine monophonic magnetic cartridges I can play ordinary r ecords
with no hum at all, on the very same amplifier. That galls me. I like stereo, but I
like standard sound better- if it has no
hum. I'm still tearing my hair_ I still have
hum and I cannot take the blame for all
of it.
Plural Trouble
Since thi s month's writing is deliberat ely
in general terms, I'll mention no cartridges
nor other equipment. But the combined
source of my hum is not hard to apportion
Gut. The trouble is never serious in anyone
place or component. It is the combination
of minor ills that makes the major one,
the sum total of hums.
]. Ster eo magnetics, so far, ar e often
very low-level as compared to well known
high-quality standard magnetics, monophonic.
2. Some that produce a healthy output
do it via t.r ansformers-and ther eby risk
jumping from the frying pan to the fire.
TrHnsformer s love to pick up hum, especially two of them.
3. Some ceramic stereo cartridges, with
high-level non-preamplified output, n evertheless produce (a) relatively low level for
this stage, requiring plenty of work on the
amplifier's part-hence more amplifier hum;
and (b) the ceramics now available t end
to rate a very high impedance input, which
makes for mor e and easier hum pickup.
Th us for a variety of 11easons, my first
batch of stereo cartridges all involve an
objectionable hum level, as compared to
monophonic standard cartridge equivalents.
4. Ster eo discs tend to b e cut lower in
level th an standard discs- considerably
lowel· in many cases. Hence-more gain
needed in the syst ems and more hum produced in t Il e fin al sound, from wherever it
may come. Bad!
5. Admittedly a somewhat special setup , my pickup connections allow for switching from standard to st er eo operation,
using either type of cartridge. In the same
manner, with standar d equipment and
standard records I experienced no hum
tT01.\ ble- but along comes stereo and I find
myself involved in a lot of private hum,
AUDIO
•
induced along the way in my own hookup.
The switch has had to be heavily shielded,
the "shielded" leads I have twisted into
odd positions to keep them as far a s possible from contamination, and so on. My
biggest unsolved problem, with the transformer- coupled stereo cartridge, is an unexplained ground loop (~) that acts this
way: When only one channel is connected
- either one-there is only negligible hum.
But when the second channel is hooked
up-either one- there is loud hum and a
a very unpleasant pickup of motor noise
from the turntable. So, at the moment,
I'm "testing" that particular stereo cart r idge on one channel only.
*
*
If I seem to grouse, and if my problems
seem particularly fuzzy and ill-assorted, I
bring them upon this generalized way simply because, the world being imperfect, I
suspect that many a home buyer of very
high quality ster eo disc equipment i s going
to run into the same t angled confusions as
to phasing and, very likely, as to hum, and
I further suspect, people b eing what they
are, that many a hi-fi dealer and, perhaps,
even many a professional engineer, is going
tc find himself disagreeably ensnared too
in a few of th ese minor but initating
plural-problems.
As I've often said, if every audio problem had one inescapable, exclusive, single
cause, if every single fault could be cured
with a single solution- then hi-fi life would
be a dream come true. Also the r est of life.
But as things usually ar e, trouble is virtually always plural trouble, a combination
of factors, a plurality of causes. And most
of us, being t ypical, find th at to pinpoint
plural trouble is the nastiest small job in
the world.
It never was more typically nasty than
in stereo hum and stereo phasing. Pluraled
plural.
(P.S. I trust th at by next month I'll be
b ack in my usual optimistic f ra.me of mind,
with most of my plural problems reduced
to singular. In any case, I'll be more specific then as to equipment and, in th e Record Revue, as to r ecords.)
I'll throw out one specific product, for
your inspection, in case you have hum troubles and haven't run into it. It's sticky
aluminum t ap e in rolls and it m akes a maryellous shielding mat erial to cover those inaccessible unshielded section s of hi-impedance lead, out of pickups into preamps,
that add to the total hum in critical situa tions.
My own hi-impedance hookup , as mentioned above, had an unshielded switch
(ster eo-monophonic) in the pickup line,
plus several sections of unshielded connection. The hum pickUp was inaudible in all
applications other than stereo disc- but
when I threw in my stereo cartridges,
something had to be done.
There ar e probably many brands; th e
stuff I got, via my engineer assistant, is
called Pressure Sensitive Electronic Adhesive Aluminum, put out by Modern Adhesives and Electronics (what a sticky
corporat e name!) of Garden City, N.Y.
Came in a. 900 foot roll, three-eighths in
width, .0008 gauge and sort of crimped. As
far as I can tell, you can make contact
through the adhesive b acking bnt to be
sure you can a.lways crimp over a bit of
the edge on each layer . It gr eatly reduced
the hum pickup at and around my hi-impedance toggle switch, and took only a few
moments to apply. Look out for accidental
sllorts with the sign al "hot" lead, though.
ew!
8 "COAXIAL
Voice Coil Im pedance
Resonan t Frequency
16 o hms
59-7:0 cps
Freq uency Range
40- 20,000 cps
Moximum Powe r
8 W
Se nsitivity
Weig ht
103 d b/ w
1. 7 kg
3. MACNETIC CARTRIDCES
It's getting so that I can't find anything
to say at all about the best of the newer
83
SEPTEMBER, 1958
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N EW .'
No. 119
HIGH FIDELITY AND THE MUSIC LOVER
by Edward Tatnall Canby
An up- to-the-minute guide that shows you how to get the
best out of your hi-Ii records and tape recorder. Mr. Canby
discusses in detail the speaker, t he amplifier , the radio tuner,
the record player and the tape recorder. He shows you how
to save time and money, and get the hi-fi equipment that suits
your particular needs. Illustrated with line drawings. $4.95
No, 110
HANDBOOK OF SOUND REPRODUCTION
by Edgar M . Villchur
Right up to date, a complete course on sound reproduction.
Covers everything from the basic elements to individual
chapters of each of the important components of a high fidelity
system. $6.50 Postpaid.
10.120
-iE 4th AUDIO ANTHOLOGY
$2.95 Postpaid
,is is the biggest Audio Anthology ever!
)nuins a wealth of essential high fidelity
low-how in 144 pages of complete arties by world-famous authors.
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N~112
TAPE RECORDERS AND TAPE RECORDING
by Harold D. Weiler
A complete book on home recording by the author of
High Fidelity Simplified. Easy to read and learn the
techniques required for professional results with home
recorders. Covers room acoustics, microphone tec\!niques, sound effects, editing and splicing, etc. Invaluable to recording enthusiasts.
.
P"pn COlier $2.95 Poslpaia.
'JMPLETE DETAILS WITH SPECIAL
FFER. IN AD ON PAGE 46.
No. 115
Mc"IOUD HIGH FIDELITY OMNIBOOK
Prepa·red and edited by C. G. McProud,
publisher ·of Audio and noted authority
and ploneer in the lield of high fidelity.
Contains a wealth of ideas, how to's,
what to's and when to's, written so
,Iainly that both engineer and layman
:an appreciate its valuable context.
:overs planning, problems with decora:ion, cabinets and building hi-Ii furni:ure. A perfect guide. $2.50 Postpaid.·
No. 114
Revised Edition
THE NEW HIGH FIDELITY HANDBOOK
by frYing Greene and James R . Radcliffe
With Introduction by Deems Taylor who says
" ... Messrs. Greene and Radcliffe, two gentlemen whose
knowledge of hi-Ii is only slightly less than awesome
. .. Read it through, and yOH will arise full of knowledge." A complete and practical guide on high fidelity;
covers planning, buying, assembly, installation, and
building hi-fi furniture. $4.95 Postpaid.
No. 118
NEW! How-to Book on Hi-Fi Repair
CARE AND REPAIR OF HI-FI-Volume
by Leonard Feldman
AUDIO Bookshelf
RADIO MAGAZINES, INC., Dept. A
P.O. Box 629, Mineola, New York
Please send me the books I have circled below • .I am enclesing the
full · remittance of $ .. :.... :... :............ ::.:...:(bIe ..
All U.S.A. and CANADIAN orders shipped postpaid. Add ·SO¢ for Foreign orders
(~ent at buyer's risk).
.
'C·.O;D\ ::.
BOOKS:
110
112
114
l1S
118
119
Latest information on hi-Ii components for efficient repair and maintenance. Complete, down-to-earth information that is not punctuated with complicated mathematics. Helpful to the hi-Ii enthurialt,
technician or engineer, this first volume includes many important
features: Example schematics with tube layouts, descriptive illustrations and hook up. . diagrams, burccs'_ guide. 15 6 pag~s profusel,
ill.cd."hd, $2 .50 ,Postpaid..
120
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'
magnetic cartridges; they all sound alike,
and they should, considering the extremely
low distortion factors present. Normally, I
don't go aI'ound AB·ing cartridges one after
the other. I prefer to put them to work on
lllusic, over a good span of time. This tells
me more of what I need to know than any
AB test.
Shure and Norelco
Two new units that recently reached me
are in this category and use the same basic
principle, a novel one, the moving magnet.
Which of them came first I do not know;
one, Norelco, comes from Philips in Holland the other, Shure Dynetic, comes from
the 'U.S ., and both produce top·quality
sound from a I'emovable stylus that is also
a magnet, oddly magnetized in a sidewise
manner so that one side of the pencil-like
shaft is North, the other South.
Whether the moving·magnet magnetic is
now the ultimate ultra I don't know. It
certainly wOI'ks beautifully and sounds the
same. Output in both of these cartridges is
enough to avoid any thought of a trans·
former . The compliance in the Norelco is
somewhat higher than in the Shure- but
this all·purpose model of the Shure Dynetic
is made somewhat more ruggedly than the
original studio Dynetic (the one on its own
spear-shaped arm), for use in changers and
in standard arms to choice, and thus it has
a slightly heavier, slightly less compliant
stylus assembly. Even so, it is plenty com·
pliant enough to give ultra-smooth response
on the loudest recorded passages. Both cartridges will zoom easily over stereo vertical
bumps. Both are well worth investigating
if you want the latest in top quality sound
in a separate cartridge, to fit in any good
arm.
I must say in all honesty, now that I
have my cartridges rigged up for frequent
and quick interchangeability, that most of
the time I can't possibly tell these superduper newer units apart. Is it the Fairchild
225, the ESL (the older model, with transformer- still a terrific cartridge), the N 01'elco, the Shure-by-itself, or the Shure-built·
into-its-own-arm ~ or the Grado~
What I hear, as you can guess, is music.
Unless something about the cartridge's performance distracts me, I tend to forget it,
in favor of the music itself, or the sounel
itself, whatever it may be.
I find it very difficult to concentrate on
the performance of an extremely fine car·
tI'idge-and this is precisely as it should be.
lf it shows no unpleasant peaks, tracks
nicely and cleanly in the loud parts, gives
enough wallop, if the stylus stays clear of
the side-guards or pole pieces (one of my
GE 78 styli keeps buzzing against the polepiece on one side- stylus !s bent a. bit)! if
dust refrains from collectlllg and Jammlllg
the point en route (wl.lich happens ple.nty
often with some caI·tndges)-then I Just
listen. That's what a cartridge is for.
It's only afterwards-after many playiugs- that I suddenly wake up one day and
say, hey, that cartridge is good. Cumulative
high performance. It's likely to be that way
with these moving-magnet jobs, the Norelco
and the Shure Professional (the separate
cartridge). At this early point they're both
too good to tell apart, my style. Give 'em
time.
Grado
I've had a Grado cartridge in use, too,
for a longer time, and am pleased with it,
decidedly. It's made like a watch, by watchmakers etcetc. but what really sells it to
me is simply the fact that it works, sounds
extremely good, is rugged so far, in spite
of a seemingly risky suspension of the
stylus, out in front of the cartridg~ . I was
sure it would break or get caught III some-
AUDIO
•
thing, but it hasu't yet, after many months
of solid use as my main radio broadcast
pickup. I've really banged it around, too,
under duress.
The compliance on the Grado is fantastic,
and the play of the projecting stylus "bar",
both vertically and horizontally, has to be
felt to be believed. It is of the type that
sticks far forward at a diagonal and in this
respect is extremely useful for all who need
to pinpoint record groove positions by eye,
as in radio stations and in all situations
where records are played by hand, by the
LP banel. 'fhis is a blessing to me.
So far-there are no quirks and tricks
along with this extreme compliance. The
stylus is still centered; it doesn't stick over
to one side of its long almost-free movement, it doesn't hit anything an d buzz, as
many styli do on provocation. It doesn't
distort when you weight it downhill sidewise, as is so easy to do with a slightly
off-level playing surface. It doesn't make
funny noises on extremes of vertical warping (the compliance allows it to track
warped records unusually easily). Altogether a reliable and top-sounding unit, so
far, with no I'eservations that I can think
of. More can't be said; if you want engineering details go check the specs yourself.
INVALUABLE NEW 64-PAGE
PRACTICAL
Volpar
Finally, still another cartridge that is
unusual, though a bit on the delicate side
for a rough user like me. The Volpar, made
in Florida, is a unique cartridge-and-arm
combo, a long, thin aluminum tube supported on a simple and ingenious nylon
bearing, the end of the tube flared out to
house the tiny magnetic cartridge, all of a
piece. No springs-the tube is counterweighted and point pressure is adjustable
by a simple screw-on weighted tube at the
rear, slightly larger in size than the armproper. Balsa wood and such aside, this. is
about the lightest arm I've seen. You pIck
it up and put it down yourself, without
handles, pushbuttons, or fingerlifts. Economical and ultra-simple.
I can't tell you at this point what construction the cartridge uses, but in working
with it for my weekly broadcast (temporarily in place of the Grado) I found
quickly that it is sensitive to sidewise pull
and, oddly, to sudden pressure from above,
as in dropping it or accidentally pushin.g
it down with a finger. Side-pull makes It
distort· the stylus is centered in a very narrow sp~ce-but stays centered very nicely
when you aren't mauling it. (To maul, in
this case, means barely to touch the featherweight arm.)
The effect of dropping this cartridge, or
pushing down gently on it, is strange-a
kind of amplitude ilutter. It sounds like a
vibrato but obviously can't be frequencymodulated. The pulsing, only for an instant,
sounds like the quick flutter when a tape
recorder starts up. It must, however, be an
oscillation that affects the output level, not
the fI'equency, and has to do, I'd guess,
with the (vertical) stylus suspens~on. U~ ­
important, but I've never heard thIS partIcular effect before. Interesting.
The Volpar was sent me for trial some
time ago, and I suspect that it was a handmade prototype. It just looks that way. If
the pickup has got into production, it
should be of considerable interest to a lot
of readers. It comes, if I I'emember rightly,
from Panama City, Fla. Don't have the
address with me at the moment. I haven't
bothered to say that the sound of this unit
appears to be excellent. Negatively speaking, I haven't noticed. anythi~g wrong with
it. Good sign, espeCIally WIth all of the
above competition. (P.S. I've found the .a ddress-it is 4404 W. 22nd Panama CIty,
Fla. )
IE
SOUND
PLANNING
HANDBOOK
COMPLETE, AUTHORITATIVE ..• ONLY $1
Over twice the size and far more comprehensive than the previous edition . . . and still
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An absolute must for engineers, technicians,
architects and servicemen!
JUST A FEW OF THE SUBJECTS COVERED:
•
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How to judge and select drivers
Mismatch and power transfer
Wide-angle vs. directional horns
Overload protection
Correct phasing
Control of reverberation
Speakers as high output microphones
Handling line matching transformers
· .. and much more . . _ all representing
the more than two decades of research
and progress in the design and manufacture of loudspeake rs which have
made the University brand world famous. Yours for just one dollar.
•
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MAIL THIS COUPON TODAY.
Desk R-7 , University Loudspeakers, Inc.
80 50_ Kensico Ave., White Plains, N _ Y.
I am anclosins $ _ _ Please send mL-coples
of the all-new 54-pase University Technilos.
1 would also like a free copy of your latest
o
Product Cataloa.
NAM~E
____________________
•
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I
I
••
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._._. __ .. _.-
•
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AOOR~' &S
________________________
CITY'_ _ _ _ _--LZONE--STAT<-E_ __
85
SEPTEMBER, 1958
www.americanradiohistory.com
AmericanRadioHistory.Com
'--CLASSIFIED'-'
CONTROL UNIT
(fTom page 21)
sively . .A. great improvement in reliability was realized by a 50 per cent
saving in parts when compared to the
contr ol unit formerly used.
PARTS LIST
112
GIBSON GIRl® •.•
TAPE SPLICERS
Six Models from 1.75 to 55 .00
• ROBINS GIBSON GIRL tape splicers
assure you of PROFESSIONAL SPLICES
IN SECONDS! They are .the accep.ted
standard of the profe ssional and Indus·
trial users of recording tape because
of their ease and reliability of
operation and high standards of work·
mansh ip. The only spli cers which cut
and trim the splicing ta~e and tape
edges with an indented trim cut,
making THE SPLICE WITH THE
GIBSON GIRL SHAPE.
AT DEALERS EVERYVVHERE
~
Write for FREE catalos of ROBINS'
Phono' and Tape Accessoriesl
~-.iir} ROBIINS
•
INDUSTRIES CORP.
FLUSHING S4 • NEW YORK
WIDE LATITUDE RECORDING TAPES
IN JHE PERMANENT PLASTIC CASE
Completely distortion free,
regardless
of i nput level; lowest noise recordings;
matchless re pro duction on ony make
recorder; lifetime l u brication e liminate s
squeal , adhesion, head d e posits; longe r
la st i ng ; highly resistant to abrasion,
p r int through a nd cupping .
FREE TAPE· TIME RULER
(tells at a glance,
time and tape left
on reel)-write to:
A lia
"'~
CORPOR A TION
LOD I, NEW JERSEY
Circle 86B
watt 5%, unless otherwise
(All resistors
indicated)
20-20/450, electrolytic
C" C,
C,
.01 !-tf, mica
.0025 !-tf, mica
C,
100 !-tf, 6v., electrolytic
C" C.
C,
0.5 JAf, 600 v ., paper
C,
0.2 !-tf, 600 v., p aper
C,
600 !J.!-tf, mica
.05 !-tf, 600 v., paper
C,,' C,.
4 !-tf, 250 v., electrolytic
C'3> C'J
Cu
.006 !-tf, mica
50 !A!!J.f, mica
C,,' Cla
.01 !-tf, 600 v., mica (Sangamo
C'" Cl ,
type H )
Fuse extractor post (Littelfuse
£,
324003)
% amp. fuse (Littelfuse 3AG)
£
J" J" J, Amphenol 80·PC2F connector
Amphenol 80·P·MC2M connector
J" J,
Phone jack (Mallory SC-1A)
Ja
Pilot light socket (Dialco
PL,
95408 )
4700 ohms, 2·watt, 10 %
R" R,
R,
12,000 ohms, 2-watt, 10%
0.27 m eghoms
R,
R,
30,000 ohms
2 megohms, 10%
R,
R,
1000 ohms, 10 %
0.1 megohms, 10 %
R,
0.39 megohms, 10 %
R,
0.24 megohms
RIO
0.36 megohms
Rl1
0.15 megohms
R"
1200 ohms, 10 %
R13
47,000 ohms, 10%
R"
75,000 ohms
R"
24,000 ohms
RIG
0.51 meghoms
R", R"
0.56 meghoms
RIO
0.16 megohms
R"
9100 ohms
R",R"
600 ohms (use two 300-ohm
R"
r esistors iu parallel )
12,000 ohms
R", R"
5100 ohms
R"
1.0 megohm, 10%
R,., R..
47,000 ohms, I-watt, 10%
R,., R"
R" , R.. 820 ohms, 10 %
62,000 ohms
R" , R"
0.39 megohms
R,,, R"
0.5 megohm potentiometer
R31
2-gang, 2-pole rota ry switch
S,
(Centralab PA-2005)
I-gang, 2-pole rota ry switch
S,
(see text)
UTC transformer shield, A-33
SH,
T,
Power transformer: 500 v. CT
at 20 rna; 6.3 v. at 2 a .
(Triad R -3A)
Input transformer-Chicago
WF-28
EF86 tubes
v" V,
12AU7A or ECC82 tube
V,
V,
6X4 tube
Miscellaneou s
3 Vector Socket tunet 8-N-9T
1 Vector turret 8-12
6 Vector socket saddle nuts 4-40U
6 Vector socket screws, S4
1 DPDT toggle switch
1 NE-51 neon bulb
1 7 -pin miniatu re socket
3 noval tube shields, 1 tit in.
1 miniature tube shield, 234 in .
1 chassis, steel, 5 x 13Jf2 x 2Jf2 in.
1 bottom p l ate, steel, 5 x 13Jf2 in.
86
lE
Rat .. : 10' per word per In,ertlon for noncommorclll
advertisem. nts; 25' per word for commercial adn r·
tl5Om.nts. Rat.. are n.t, and no dlscounb will h
allow.d . Copy must b. accompanied by .. mlltan.. In
fu ll . and must reach the N.w York om.. by the
flr at of th e month preceding t he date of In utl.
THE AUDIO EXCHANGE h as the largest
selection of new and fully guaran teed u sed
equipm ent. Catalog of used equipment on
request. Audio Exchange, Dept. AE, 159-19
Hillside Ave., Jamaica 32, N.Y., AXtel 7-7577;
367 Mamaroneck Ave., White Plain -', N.Y.,
WH 8-3380; 836 Flatbush Ave., Brooklyn,
N.Y. , BUckmiuster ?-53 00.
HIGH FIDELITY SPEAKERS REPAIRED
A.nprite Speaker Service,
70 Vesey St., New York 7, N.Y . BA 7-2580
LOOKING FOR CLEAN RESPONSE TO
20 CYCLES 'I Listen to the rad ically new
Racon "Hi-C" 15" foam-suspension speake r.
Racoll Electric Company, IIlC., 1261 Broudway, New York 1, N.Y .
ENJOY PLEASANT SURPR I SES? Theil
write us before you purchase any hi-Ii. You'll
be glad you did. Unusual savings. Key Electronics, 120 Liberty St., New york 6, K .Y.
EVergreen 4-6071.
WRITE for confidential money saving prices
on your Hi-Fidelity amplifiers, tuners, speakers, tape recorders. Individual quotations
only; no catalogs. Classified Hi-Fi Exchange,
A R, 2375 East 65 St., BrOOklyn 34, N.Y.
TRADE f or new-used AMPEX's. Gro"e Enterprises, Roslyn, Pa. 'l'Urner 7-4277.
HI-FI HAVEK- New Jersey's leau iug
so unu Cen tel'. Write for information on unique
mail order plan that offers professioual auvice and low pr ices. "Awarded Iastitute of
High Fidelity Mauufacturers P lacque as
Registered Component Dealer." 28 Easton
Ave., New Brunswicl{ , New Jersey.
Was il.
PERMOFLUX: Only tru e hi-fi headph ones;
Binaural $;;5, Monaural $33 , Postpaid. Foran,
3452 N. Hackett Ave., Milwaukee, Wis.
AMPEX 350, fu ll-track, 7% - 15 ips, eith er
console or portable cases. Excellen t condition, less than 100 hours. $795. R. J.
Entringer , 2211 Camino Del Re po so, La
Jolla, Cal.
WANTED: GE S1201D speaker, will pay
$12. Eugene Roy, 5 Hillside St. , Ha \" el'hill ,
Mass.
U. S. GOV'T surplu s Grade 1, Class A audio
transformers. ± 1.5 db to 20,000 cyc les. P" imary 7500 ohms, 15 ma d.c. Secondary 600
ohms split, 2 rna d.c. max . Size 2 x Ill., x P h
in. Only $1.00 each. Add 25 ¢ ea. for postage
a n yw here in th e U.S.A. Transico, Box 269,
Bronxville, N.Y.
FOR SALE : Hewlett-Packard VTVi\l 400D
$135 ; Audio oscillator 200CD $90. Excellent
con dition. Fairchild 201-B turret transcription arm $25. A. C. Smrha, 12 Moun tain view
Dr., Westfielu, N.J.
WANTED: Useu RCA RT-3 tape recorder.
Also Scully lathe. R. H. Holsclaw, 2912 E.
Mabel, Tucson, Ariz.
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
.
FOR SALE: Model TWD Concertone 20/20
tape recorder deck, and TWA preamp. Also
Hartley-Luth 220 Type "A" speaker. Kenneth E. Gould, 509 Vine St., Liverpool. N.Y.
SCOTT 210-C Dynaural amplifier; with
case. 1st class condition. Last one; ou ly $95.
B. K. Balch, 611 Livingston Rd., Linden , N.J.
FOR SALE: Presto K disc recorder and
P.A. unit. 33% & 78 rpm. Takes 13 1h"
masters. Microgroove feed screw available.
Webster 80 wire r ecorder, la test head. Box 3,
New Britain, Conn.
NEW, wired, tested, Dynak its, Mark Ill's
$86.00; Marl, II's $76.00, F.O .B. Stnart
Quint, 3 Grandview Aven ue, Peabody , Mass.
FOR SALE: Presto 900-R2 tape mechanism aud custom-built recorder po\\,er supply, $250. Details on request. Walter C reed.
1202 Atwood Road, Phila. 31, Pa.
FOR SALE: V-M Model 750 staggeredstacked, ste reo tape recorder. Will sh ip in
orig ina l factory carton . $215. Walter Zela~'a ,
140 Amanda St. , Clyde, Ohio.
WANTED: RCA 73-B or similar disc recorder with stationary overhead lathe mech ani m. State condition and price. Star Record;'lg Co., 1615 London Rd., Duluth 12, Minn.
FOR SALE: Fisher 80-R AM/ FM tuner.
Heath WA-P2 preamp. McIntosh 20\\12 Amplifier. Excellent conuition. Best oll'e r ove r $1;;5.
D. Kilbl'ith, 1722 California Ave., Sea ttle 16,
•
SEPTEMBER, 1958
PROFESSIONAL
DIBE£TOBY
HIGH-FIDELITY HOUSE
Most complete stock of Audio
components in the West
Phone: RYan 1-8171
536 S. Fair Oak" Pasadena I, Calit.
Circle 87C
!~~E~
Get more FM stations with the world's most
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~ll~·
Send 25f1 for booklet "Theme And Va ria·
- .
tions" con t aining fM Statio n Dire ctory.
\~~.~
APPARATUS DEVELOPMENT CO.
-;:::;:::-
Wethersfield 9, Connecticut
Circle 870
'
CANADA
High Fidelity Equipment
Complete Lines •
Complete Service
Hi-Fi Records - Components
and Accessor ies
8LECTRO~UOICE
SOUND SYSTEMS
141 DUNDAs-ST. WEST. TORONTO, CANADA
Circle 87E
SOUND
CO R
PORA TI ON
Circle 87F
POWERING
1nJu~ /Vote~ ••• 4 OUT OF 5
H. H. Scott, Inc., M a yna rd, Ma s s ., r e cently receive d two a w a rds for compa ny
adve rtis ing from the N ationa l F e d e r a tion
of Advertisin g Agenci es. One w a s f or the
bes t consum e r a dvertising in 1957, while
the o the r w a s fo r the b est s ingle a d of
the y ear. Presenta tion of the a w a rds w as
m a d !l to H e rmon Hos m e r Scott, c ompa n y
p.r ~s Id e n t, a nd Ma r v In Gro s s m a n, a d ve rtISIng m a n a g e r , by H a rold S. G oods t ein
v i ce ~p! es id e nt of Arnold & Co., Sc ott ad ~
ver t ISIng age n cy. P a rticipating in t h e
com petit ion w ere m or e t ha n 200 agen c ies.
Sidn ey F rey, p r eside nt, h a s a nn o un ce d
pla n s f or Audio Fidelity, Inc., t o en ter
t h e c lassIcal r ecord fie ld. Present thinkin g
call s fo r the r elease of m on o phoni c a nd
s ter eoph onic. r ecord a lbums, a s w e ll as
t a p es, r a ngmg f r om lig ht c lass ical to
ver y seriou s works . Ema n u el V a rdi w e llkno~n v iolinist a nd conduc tor, h a s b ee n
apPo I,n te d to .h ead up the Audio Fide li ty
~~~~~~ cal A rtI s t s a nd R e p e rtoire d e partAltec Lansing COl'pora tion is the la t es t
o f th e m a j or compon e nt manufa cture r s to
e n~ e r. the fi eld of p ack a g ed high fidelity.
WIthm the n ear futur e t he firm will introdu ce t wo hi -fi con s oles in furnitur e s t y l ed
by Glenn of California . Both models incorporat e a Garr ?-rd r ecord c h a nge r, with
a ll ot h e r co mp on e nts , including a n FM-AM
tun e r, ma~ufa,c tur: e d by A l tec L a n s ing .
Alth ough dIs tnbutlOn h a s b een e sta blis h e d
in t h e . New York a r ea, Altec i s c urrently
sear c hm g fo r sales r e prese n ta tion i n o th e r
pa rts of th e co u ntr y, according to H . S.
M orri s , Altec produc t sal es m a n a g e r.
Natio nwide sales a nd m a rketing of
Madison Fielding high-fidelity compon e nt s a r e n ow b ein g h a ndled by Brand
Products, Inc., n a tiona l s a l es organiza tion
acco r ding t o j oint a nnoun cement by th~
two compa ni es . P a rticipating in the s t a t em e nt w e r e L eona rd F eldma n, pre side nt,
and B e n Bra un, m a rke ting direc tor f or
~ad i s 0l1 Fieldin g , a nd Mort Wimpie, pres Ident of B r a nd Products , Inc. A ll a d verti s ing a nd sal es p ro m oti o n , as w ell as t h e
ac tua l m echanics of sellin g Ma dison Fie lding equipme nt, will b e h a ndle d throu g h
the Bra nd Produ ct s offi ce a t 11 Lorim er
St. , Brooklyn, N.Y.
Daystl'om Incorpora.ted, of whic h Hea.th
Conlpany is a s ub s idia ry, r ec ently a nnoun ce d the for m a tion of Daystrom Linlited of England, a div is ion of Daystrom
International. The n ew British fac ility
will m a nufacture a c omplete lin e of
Hea thkits in a n ew 10,OOO-sq.-ft. building
in th e gen e r a l vicinity of London. The
Ame rican H eathkit line will be adapted t o
Britis h r equir em e nts, a nd a ll of the pa r ts
will b e m a nufacture d in the United Kin g d om. The n ew Britis h company i s exp ected ultima t el y t o service not only th e
U ni ted Kingdom, but a ll of the w orld's
s t e rling a r eas, according t o W. H. W estpha l, gen er a l m a n ager of D ays tro m Internation a l. Daystr om-Limite d d o -it-your self
H eathki ts are expect e d t o find ra pid accepta n ce b y B ri t is h indus try a nd con s umers a like s in ce t h er e will be n o d ollar
purc hases invol ve d, Mr. W es tpha l said.
Ma n aging director of the n e w D a y str om
op e r a tion will b e A. E. B. P e rri go, f o rm e rly w ith t h e Brit is h firm of P a rkins on
a nd Cowan In strume nt s .
LOOK
no further • • . if you're
searching for hi-fi savings.
Write us your requirements now •. .
Key Electronics Company
120·K Lib erty St., N.Y. 6, N.Y.
EV 4·6071
Circle 87C
ARKAY Offers
Reg ular 35 ¢ book
"Le t 's Talk About
STEREO." The Complete story of STEREOPHONIC SOUND, No cost or o bligation. Available nOw only from your
local dealer .
FREE
Circle 87H
AUDIO
•
Edwin Cornfield, executive secr e t a r y of
the In s tit u te of H igh Fidelity M a nufact urers, r esig n ed effective Au g ust 1. H e
h as j o in ed B ritish Indus tries Corpor a tio n
in a n execu t i ve sales capacity . His pos ition w ith the I ns titute h as b een ass um ed
b y Abrahanl Schwartzman, according to
Joseph Benjamin, In s titu te pres ide n t. Mr.
S c h war t zm a n h as b een in t h e m agazin e
publishin g b u s i ness as e ditor a nd publis h e r fo r 30 y ears, m os t r ecently as
publi s h e r- editor of the "Br ooklyn Queen s
Sta nda rd."
Thomas J. Nicholson, hig h -fidelity sal es
m a n ager f or t h e G e n e r a l El ectric Compa n y f or th e p ast e ig ht year s, has j o in ed
Amp ex A udio, Inc. , a s w es t ern zone m a n:agel' . . .. Robert G. B a ch h a s anno unced
his r es ig n a tion as s a les a nd a d v ertis in g
m a n a g e r of F a irchild R ecording Equipm e nt Corp or a tion in orde r t o dev ot e his
eff or ts to pro m otio n of F a irc hild highfidelity co mpo n e n ts in the N ew Y ork a r ea
a s a n i n d e p ende nt s a les r e presenta tive .
B ach Sa l es Co mpa ny will h eadq u a rte r at
26 M a h a n R oad, Old B e thpage, N.Y.
SEPTEMBER, 1958
of the world's
greatest hi-fi
amplifiers
the
Arnperex®
6CA7/EL34
~
~
HIGH·POWER
OUTPUT PENTODE
No other comparable tube combines to the
same degree the 6CAl's exceptional
linearity, high power dissipation and low
drive·voltage requirements. It is a true
penta de design, with a separate suppressor
grid that controls the space charge, resulting
in greater linearity on reactive speaker
loads than is possible with competitive
beam·power tetrodes. A single pair of
6CAl's in push-pull has been successfully
used in power amplifiers delivering up to
100 watts undistorted output.
Ask your Amperex distributor about Amperex voltage
ampUfier, reclifier and output lubes for hi-Ii circuits
Arnperex
ELECTRONIC CORP.
230 Duffy Avenue
Hicksville, L.I., N.Y.
Circle 87A
the incomparable
.Ee""II.,aph
[email protected]
tape recorders
Ferrograph Stereo eq uipm ent is de signed to meet traditionally exacting high
quality standards.
T wo superb models aTe available :
The Ferrograph Stereo 88 is designed
for both recording arid playba ck of stereo
tapes. Professional quality twin-recording
amplifiers and playback pre-amplifiers
are inbuilt. Monaural recol'ding/ playback
on both tracks is . also possible.
The Ferrograph Stereo 3S is designed for
the playback of stereo tapes and a lso
offers all the f eatures monaurally of the
popular F errograph 3A Series. While it is
possible to employ auxiliary amplifiers,
the Ferrograph "Stere-ad" unit offers the
ultimate in matched amplifiers resulting
in superb stereo r eproduction.
Limited production and heavy demands
will delay delivery. See yOU?' local dealer
and place your order now!
£RCONA CORPORArlON
(Electronic Division)
16 W. 46 Street, Dept. 77, New York 36, N. Y.
In Canada: Astral Electric Co. Ltd.
H Danforth Road, Toronto 18
Circle 878
87
www.americanradiohistory.com
AmericanRadioHistory.Com
ADVERTISING
Sound
Tall(
by fohn K. Hilliard
Director of Advanced Engineering
WHAT SPEAKERS FOR STEREO?
Sound engineers agree that the finest
stereo reproduction can ·be achieved only
by two identical speaker sys tems of exceptional qu ality. Short of this ideal, howeve r,
the premise is muddled by an ever-increasing number of unfounded claims ... most
of them based on sales philosophy rather
than scientific fact.
-Actually, the proper selection' of stereo
speakers is quite clear. Du e to certain
psycho-acoustic effects, .one exceptional
speaker system and one of moderate abilities will provide better stereo than matched
speakers ,of intermediate quality. This is
only true, however, if the lesser speake r
meets certai n requisites.
The two speakers must be similar in frequency response and character. In the high
end of the spectrum the;' n ~s t have the
same limits. At the low end, they must be
similar down to 100 cycles. Below that
point, the performance of the lesser
speaker is relatively unimportant.
If the lesser speaker goes down to only
300 cycles or has major irregularities in its
r.esp ons e, a phenomenon c a lled the
"orchestral shift" will occur. This shift
results from the fact that the sound from
ar;ly given instrument is reproduced from
both speake r sys tems. The comparative
loudness determines the auditory location.
If an instrument is "placed" in the lesser
speaker and then plays into a frequency
range where that speaker is inefficient, it
will then be louder in the better system
a nd will appea r to shi.ft to that better
system.
Speakers that are inefficient below the 300 •
cycle point will not provide true stereo.
This is obvious because the 300 cycle point
is above middle C on the piano, 70 cycles
above the primary ' pitch of the female
voice and nearly 200 cycles above primary
male pitch. For full stereo it is therefore
imperative that the lesser speaker efficiently reach at least 10'0 cycles.
All ALTEC speaker systems are similar
in their exceptional smoothness of frequency response, have a high frequency
limit of 22,000 cycles, and are efficient
below 100 cycles in the lower range. This
regularity in response, range, efficiency
and quality is the reason why AL TEC
speaker sys tems are noticeably superior
for stereo reproduction.
For further information concerning the
best elements for stereo, write, ALTEC
LANSING CORPORATION, Dept. 9A-B,
1515 S. Manchester Ave., Anaheim, Calif.,
161 Sixth Ave., New York 13, N. Y. 12-3.
CIRCLE 88A
INDEX
•
Acousti c Resea rch , Inc. " ' , .. , ... ,..
Allied Radio Corp.
' ........ . , . .
Altec La nsing Corporation .,.
43 , 58,
A mperex Electronic Corp. " . . ... . ....
Ampex Audio , Inc , . , . , ., .... '.' .. .. ..
Apparatus Deve lopment Corporation . .. .
Arkay
, ... , , . ' . .. . ..........
Audio Bookshelf ... , ... , " , . .. . , ..•.
Aud io Devices, Inc , ..... ,., ..•• " ' .. .
A udio Engineering SOC iety , ....• . . • ' ..
Audio Fidel it y, Inc. ............. 61 ,
Audiogersh Corp.
, . . . ....... . .
Aud iospeaker Laboratories ... . . .. . . ...
71
67
88
87
52
87
87
84
75
48
69
6
78
Belden
, . , , , . '. , ........ . . ..
5
Be ll T e lephone Laboratori es ., ... , .. , .. 16
Bogen, Dav id , Co" A D iv ision of The
Siegler Co rpo rat ion ... , . .... .. . Cov. II
Boz ak, R. T" Sales Company . . . ... . ... 39
Bradford Audio Corp. ,," ' ...... , . . .. 74
British Ind ustries Corporat ion. facing p. I , 3
Classified
" .. . .. , . ... . . . ... . . . ..... 86
Dy naco, Inc ,
, . . . .. , • ........•. . . 88
EICO .. ....... .. . .... . ... .........
Electro-Son ic Labo rat or ies, Inc. . .... ..
Electro-Vo ice, Inc, " , . ...... ,. Cov.
El ectro- Voice Sound Systems .....•. .
Ercona Corporat ion . ' • . , ..... .. . . ... .
Fa irchild Reco rdin g Equ ipment Company
Ferrodynamics Corporation ... , . , . , ...
Ferrogr aph Stere o .. , .. .. ...........
Fisher Radi o Corporation , ........ , . . .
Frazier " . .... ....... . , •••••••••• ••
Fukuin Electr ic I Pioneer ) .........•. '
13
65
IV
87
87
Featuring para·couj1!ed
windings , a new design
principle (patents pend·
ing). These transformers
use advanced pulse tech·
niques to insure supe·
rior square wave per·
formance and undistort·
ed reproduction of tran·
ents . Dynaco transformers
full rated power over the
entire audio spectrum from 20 cps to
20 kc , without sharp rise in distortion at the
ends of the band which characterizes most
transformers. Conservatively rated and I!uar·
anteed to handle double nominal power from
30 cps to 15 kc without loss of performance
capabilities ,
Specifications
Response: Pl us or minus 1 db 6 cps to 60
kc , Power Curve: Within 1 db 20 cps to
20 kc. Square Wave Response : No ringing
o r dist o rtion from 20 cps t o 20 kc. Per'missible Feedback: 30 db ,
MODELS
A-410
15 walts EL-84 , 6V6, 6AQ5
14.95
A-420
30 walls 5881, EL·34, KT ·66 19.95
29.95
A-430
60 walls KT ·88, EL·34
A-440 120 walls KT -88, 6550
39.95
A-450 120 walls PP par KT ·88, EL·34 39.95
(all with tapp ed primaries except A·440 which
has tertiary for screen or cathod e feedback )
Additio nal (lata on Dynakit and Dynaco components available on request
including circuit data for mode"niza,tion of Williamson-type
amplij!ers to 50 watts oj output an(Z otlle,' applications oj
DIJ IW CO t,·ansjonne,·s.
.DYNACO INC.
47
86
87
35
56
83
Export Division: 25 Warren St., New York, N. Y.
General El ectric Company . . . ,. . ...... 33
Grado La boratori es, Inc . . . . ,... . . .....
2
Grommes- Di v ision of Precision Elec-
tronics, Inc . . . . . . . . . . ....... . ..... 49
H artl ey Products Company . ' .... . .. ,' 66
H eath Compa ny . ......... ........ 7-11
H igh Fide lity H ouse ........ .. . . ... ' 87
J" nsen Man ufact uring Company • .. • " . 29
Key Electron ics ' ...... . ... , . ...•. , .. 87
Kierulff Sound Corporation ... , _ . .• ,. 81
KLH Resea rch & Deve lopment Corporation ., ....... " , . ... ... . . .. ... .. 64
Lansi ng, James B., Sound, I nc .•...•..• 77
Leonard Radio, Inc. . .. .. ... . ... ... .. 8 T
Ma rantz Company . , ........ ..... . ... 70
M ullard Overseas Ltd. . , .•.. ' . , .. ..• ,. 45
ORRadio Ind ustries , Inc. ' • • . ' ........ 76
Pentron Corporation .........•••. • • ••
Pickerin g & Company, Inc . . . . . . .. . ••.
Pi lot Rad io Corporati on ... . ..... . . . ..
Precise Development Corporation .. ....
Profess ional Directory .. .. . •.•.• ... • ••
79
Racon El ectric Company, Inc. .•.... . ••
Radio Corporation of America.
Cov.
Rek-O-Kut Co., Inc . . . . . . .. .. .• ••...
Rigo Enterprises, Inc. .........•.• . • , .
Rob ins Industries Corp . . .. ..... ..... .
Rockba r Corporat ion .... • •••... •. •..
80
II I
73
4
86
41
15
31
37
87
If cancer is detected in its
early, localized stage, the
chances for cure are very much
better. Play it safe and smart.
See your doctor for a checkup
every year.
And fight cancer with a check!
Sherwood Electron ic Laboratories, Inc. .
1
So not one Corp. . . . , . . . . ..... . ... .... 63
Stromberg-Carlso n, A Division of Genera l
Dy na mics Corp orat ion
50, 51, 53, 55 , 57, 59
Tung-Sol Audio Tubes .•.• .• • .•.. .• '. 54
University Loudspeakers, Inc . . •..• • ..• 85
88
post office
-NOW
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
4
Mail it to
CANCER, in care
of your local
•
•
AMERICAN
CANCER
SOCIETY
SEPTEMBER, 1958
}
,
RCA-6973 ... miniature
beam-power tube makes pra ctical
the design of compact, low cost, high-fidelity audio amplifiers.
The "combo" takes off! Just a "small" group of musicians, but
they've got the "big" sound, Jazz provides performers with a
gratifying means of self-expression, allows creative talent freedom to range the gamut of emotions, Designers of amplifiers
for music reproduction, too, express their talents in meeting
the challenge of compactness and power demanded by today's
devotees of high fidelity, RCA's development of the 6973 gives
the design engineer the "vehicle" for modern design,
A 9-pin miniature, RCA-6973 offers a combination of features
well suited to compact quantity-produced power amplifiers, It
is capable of delivering up to 20 watts of power output in
push-pull class ABI service with total harmonic distortion of
only 1.5 % , Double-base-pin connections for the grids more
effectively conduct heat and keep the grids " cool" in operation,
This minimizes grid emission, permits the use of high values
of grid circuit resistance, and enables practicable economies
by reducing grid-driving power requirements. High power
sensitivity, stability, dependability, and low heater power, too,
make RCA-6973 the designer's "choice" for high-fidelity amplifier designs in the modern trend to " small" size-"big" sound!
Your RCA Field Representative has complete information.
Call him today. For Technical data, write RCA Commercial
Engineering, Sec. 1-91-DE, Harrison, N. J,
RCA FIELD OFFICES
•
U
RADIO CORPORATION OF AMERICA
(!)
Electron Tube Division
E A S 10
744 Broad Street
Newark 2, N, ), • HUmboldt 5 · 3900
MID W EST :
Suite 115.4, Merchandi$e Mart Plaza
Chicago 54, III. • WHitehall 4·2900
Harrison, N. J.
WE S 10
6355 ' E, Washington Btvd ,
Los Angetes 22, Calif. • RAymond 3·8361
www.americanradiohistory.com
AmericanRadioHistory.Com
,i
4-way corner
4-way lS-inch
s peaker system
costing betWeen
12~jnch speaker
system costing
between
$325 and J.~75,
$325 and $375
such as the .
E· V CO'rlton' IV ."
INot $3591
such as the
E-V Centurion IVE
INet $365)
4
3-way lS-inch
speaker system
costj'19 between
$375 and $400
such as the new
E-V Regency III
INet $393)
4-way corner
lS-inch speak~r
.yitem costing
between
...waycorner
lS·lnch speaker
system (osting .
between
$400 a.nd-$480 ·
$480 and $600
su(h 'QS the
such as the
E·Y .C ardlnaIIY
E·Y Georgian 600
IN.t $4901
. (Net $425)
4-way .ome, Il..Jnch .peak.r
sys'em (OltinS over $600
sveh al the Incomporable
E-V 'alricla. (patrician IY
Traditional, $970,
Pa.rido" 600 Contemporary,
$119 N.n
you need the
totally
compatible
STEREO CARTRIDGE
Thousands already in use prove it
ploys all records better: unexcelled for
i
stereo; superior even to your present
cor·fridge
cal and
channel
between
for moncural. Highest verti·
horizontal com pliance. Besl
separation: over 20 db
enannels. Flotte st responses ;
flot beyond audjbility to RIAA curve.
Hum and rumble ore lor below any
magnetic cartridge. Two ccromic elements deliver precise RIAA curve with .
no huml Exclusive eN Built-in Rumble
Suppressor allows record changer use
for stereo, .7 mil replaceable (diamond
Of sapphire) stylus is ideol size .. .
gives bettor reproduct ion, longer
record wear.
The I-V Totally Compatlbl. Steroo
Cartrldgo I. the Industry's standard.
Choo•• the modol to fit your n•• ds:
MODEL 210-Ste,eo with .7 mil Oio·
mond Stylu • ••.. . •. . . Nel $19.5()
MODel 26 OST- Dual Sty lu~ Turnover
from .7 mil Diamond St~reo to 3 mil
Sapphire Monaural. . . . Net $22.50
or the EaV Velocity St.r.o Cartridge
MODEL 2lMO-Ste,eo with .7 mil Oia.
mond Stylu •... . . .•. . Net $19.50
MODEL 26MDST-Dual Stylus Turnover
from .7 mil Diamond Stereo to 3 mil
Sapphire Monaural. ... Net 522.50
Then choose a second amplifier Dnd
pre-amplifier. If this is your initiol high
fidelity system, starl with any stereophonic dual amplifier-pre amplifier .
Ploy monaurally until you odd a second
for ste reo .
Fw.ll'lo'f in ( 1.(ltO· ACOUlllCt-M. ;(~ phol'l' . 'honG·C. "
h ld,iII •• H IV~ . f:d .lity lo ,,~:hp .. ohrl ond [ lItIIUV.... ,
'..,bUt .Add .... $peo"'''' Mor in"
[VI ~
" ..hmo' fl,Won;( Itnlrvlllt nh Gnd Millt.ry Mol.,I.'.
"""",,,,",,11.
1
Add-on the E-V
CARLTO~ l.v .- . I
DUCHESS lYE
Une xce ll ed for purity
of ton e and rang e
through highly de . . eloped 4-way driver
system. Super -effi_
cien t , smooth respons e throug h use
of diffraction horns
to give wide stereo
listening area; bo ss
is especia ll y e)!:tended in range through
EN Pho se -Loading
p rinciple with J2"
driver mounted low
and at rea r of enclosure . Compares in
performance to corner horns.
Net $292
Co"'poct, d.luxe
Kllpoch·IIce. Hd .....
o rate 3 - way laud ..,
spedk., syste m fa r
Compelnlon piece,
matche. Arl.tocrot
III, UNS SQme driver
sylt. m. Designed to
s moo t h, e ff icien t
_role optlnwm/y In
wide-ra nge , e p ro-
al_.the.wa/I posi-
ductlon. U... folded
hom throat in cam-
tion where a com.r
pact furmf"ril" p;~,e
of p/ecnlnll pro......•
1iGn.. Th~ wall. of the
1MtI1I_ and the
......., ' .... Ihe large
hom ..outh requl,ed
for lowest ra nge
..._ . D1ffrac11an
and
...... In,....
,_irt-
I. . .. .....noble.
Net $303
Deluxe venion of the I
Duchess IVE' in~ smart, . t
handsome lo~ ~b~y
design; harmonizes
gracefully with ";any .
. mode r-n furnishin'g ,
m'odes: A complete
Phase - loaded Sys.
. ' tern , aHortling . unusual bass; ~.~$ po:ns,e
with 'smooth, ' reso~ f
naf'\ce~iree charaCter-. '
istics. includes aelux.e
15-inch indire~t be;s
d rive r 4-w~y com.POncnts.
~hIgh
IUfeloesl ...... _ ,
'.1
New complete 4-way
system incorpora ting
all design features of
the magnificent EN
Georgian. but on a
smaller scale. Uses
Klipsch "K'" folded
horn with EN delu)!:e
12-inch indirect-radiator speaker system,
112WK IF ddve,. MT.
30 coaxial mid-bllss
and treble assembly,
T35 VHF driver arid
X336 crossover). Response from 30 cps
to beyond audibility.
E~Y
Add·on the E·Y
Add-on the E-V
Add-on the
REGENCY 111
CARDINAllY .
GEORGIAN 600
The versatile Regency
III delu)!:e separa te
3-wa y system ollow's
operation in the corner for full bass efficiency or along the
wa ll for convenience,
Powerful IS-inch boss
driver crosses over at
800 cycles per second to diffraction .
type treble and very
. high frequency components to give maximum dispersion and
full ste reo effect.
Authentic EN KUpsch
horn - noled for
deep 'fu ndamental
boss ron'g el complemen,ed by diffradion ,
principle ' i~ cOaxial .
~ mid-boss and treble
Utilizes same horn
co nstruction and
dri . . er complement of
Cardinal IV enclosed
by beautiful contemparory housing functionally styled by
Robert W. Fuldner.
high frequencies -i,n•
Net $490
'(K"
d,iv~r ass~mbly., Ve"y
t· . sure . realism . 9ver
broadest iivin~ ' room
oroos.
.'
.
iiet$42~::
World's largest, most deluxe loudspeaker system for those discriminatin9 liltenetS who demo"d
ultimote tonal perfection_ The
epitome of style combined
with peak performance for
the ultimate illusion of reality.
Available as the Patrician IV in
traditional styling.
Pahician 600 in Fuldner·deslgned
contemporary housing.
Net $819
Special m'odel, available to
cuslom-finish specifications . _ . at
higher price •
Net $393
Net $365
... ~.;'
• . . . . . . 0 .....
The all-new Electro-Voice speaker system that solves your space problem - saves
you money_ Whe re space doesn't permit you to add a second full-range speaker,
a Stereon is the answer. It's compact, because the Stereon reproduces only those
frequenci es NEEDED for stereo (boss below 300 cps does not contribute to the
ste reo effecl . . . so bass from both is handled by your PRESENT full -range speake r
through the accessory XX3 Stereon Control Filterl.
Stereons have the finest E~V mid-boss, treble and high frequency components,
(Frequency response: 300 to 19,000 cps).
.... . . . Net $129.50
STEREON III for high efficiency systems. , .. .
........ Net $30.00
XX3 STEREON CONTROL ......•.......
NOTE: All E-V Systems also available in limed oak or walnut finishes .
www.americanradiohistory.com
AmericanRadioHistory.Com
Systems shown ore bul a few of Ihe
multitude of E-V combinations found in
every price closs. Ask 'tour dealer or
write ~Iectro.vojce for information on
the industry's most complete line of
high fidelity speakers and enclosures.
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